reference

N3SIR 85-3160 CO

Noticeability of Features of

Secure Documents

NBS

Publications

""KW OC I Lvll LjlLuh

A 11 ID 5 Tfl 3 M 2 3

Belinda L. Collins

Suzin E. Mayerson

James A. Worthey

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Building Technology

Building Physics Division

Gaithersburg MD 20899

July 1985

Sponsored by: “ ireau of Engraving and Printing

p S. Treasury Department

ashington, DC

U56

85-3160

1985

NBSIR 85-3160

Hvnot u i OF ST

NOTICEABILITY OF FEATURES OF

SECURE DOCUMENTS

Belinda L. Collins

Suzin E. Mayerson

James A. Worthey

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Building Technology

Building Physics Division

Gaithersburg, MD 20899

July 1985

Sponsored by:

Bureau of Engraving and Printing

U.S. Treasury Department

Washington, DC

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

ABSTRACT

A review of the literature on the noticeability of features of counterfeit

bills, primarily British pound notes, is presented. The review suggests

that prolonging the attention paid to a banknote may be a counterfeit deterrent.

Various design options are suggested. A pilot study on the noticeability of

features of counterfeit US dollars is also presented. The study includes both

spectroradiometric measures of the chromaticity and luminance of a set of

counterfeit bills and an identification study. In the identification study,

21 participants selected counterfeit bills from a much larger stack of genuine

bills. They also listed the features they noticed as they made their selection.

Each participant successfully identified about 80 percent of the counterfeit

bills, although only one counterfeit was identified by all participants.

Features noticed included problems with the portrait appearance, lack of detail,

color (both of the paper and the green seal), contrast, and feel. Participants

also made errors with genuine bills, although they noted fewer features and

often mentioned printing press defects.

Keywords

attention; chromaticity; counterfeit bills, counterfeit deterrent; identification

luminance; spectroradiometric measures

iii
FOREWORD

This report is one of a series documenting the results of NBS research in

support of Bureau of Engraving and Printing Contract No. V-0283-09, entitled

"Noticeability of Features of Secure Documents. " The report summarizes

research conducted from January 1984 to February 1985.

ACKNOWLEDGEMENTS

We wish to acknowledge with special thanks the interest, cooperation, and

encouragement of the sponsor's Technical Project Officer, Dr. Edmond L.

Graminski, Chief of the Office of Research and Technical Services as well

as the help of the Secret Service. In addition, Russell Kirsch provided

essential insights throughout the project, while Arthur Rubin gave thoughtful critiques of the final report.

iv
TABLE OF CONTENTS

Page

ABSTRACT ill

FOREWORD iv

ACKNOWLEDGEMENTS iv

LIST OF TABLES vi

LIST OF FIGURES vii

EXECUTIVE SUMMARY viii

1. INTRODUCTION 1 1.1 Information on Design Characteristics

of Counterfeit Bills 1 1.2 Perception Research 3 1.3 Visual Capabilities 4

1.4 Tactile Capabilities

1.5 Olfactory and Auditory Capabilities 8

1.6 Expectations 9

1.7 Recommendations for Banknote Design 15

1.8 Relevance of Stillitz' Research to U.S. Currency 17

2. APPROACH 18

2.1 Stimulus Material 18

2.2 Pilot Study Design 19

2.3 Background - The Problem of Analyzing Detection Data 20

3. RESULTS 25

3.1 Overview 25

3.1.1 Detectability of Counterfeits 25

3.1.2 Accuracy of Identifying Individual Bills

3.2 Features of Bills Noticed During the Pilot Study

3.2.1 Comments Made During the Examination 30

3.2.2 Portrait Data 45

3.3 Spectroradiometric Data 45

3.3.1 Measurement Data for Counterfeit Bills 48

3.3.2 Measurement Data for Genuine Bills

4. CONCLUSIONS 62

4.1 Discussion of Pilot Study Data 62

4.2 Recommendations and Conclusions

5. REFERENCES 67

APPENDIX 1-1

v
LIST OF TABLES

Page

Table 1. Participant Decisions About Counterfeit and Real Bills 27

Table 2. Frequency of Errors Made in Identifying Counterfeit Bills .... 29

Table 3. Frequency of Errors Made in Identifying Genuine Bills 31

Table 4. Total Number of Comments in Each Category for Each Bill Type . 35

Table 5. Number of Comments in Each Category for Each Bill 36

Table 6. Reported Experience with Genuine and Counterfeit Money 46

Table 7. Mean Chromaticity Data in Uniform Color Space for Selected

Spots on Counterfeit Bills 54

Table 8. Mean Reflectance Data in Munsell Value for Selected Spots on Counterfeit Bills 56

Table 9. Chromaticity and Reflectance Data for a Selected Set of

Genuine Bills 60

Appendix Table 1. Instructions to Participants in Counterfeit Pilot

Study 1-1

Table 2. Comments for Each Serial Number 2-1

Table 3. Decision Processes Reported by Participants During

Debriefing 3-1

Table 4. Measured Chromaticity and Reflectance Data for

Counterf it Bills 4-1

Table 5. Measured Chromaticity and Reflectance Data for

Genuine Bills 5-1
LIST OF FIGURES

Page

Figure 1. Hypothetical ROC curves showing effects of shifting

criteria and stimulus detectability 23

Figure 2. Detectability of counterfeit money for 21 observers presented

in ROC format 26

Figure 3. Uniform Color Space Showing Area of Interest for Currency

Chromaticity Measurements 49

Figure 4. Chromaticity data for three areas of counterfeit $10's and

$100’s presented in 1960 Uniform Color Space 50

Figure 5. Reflectance of measured spots on counterfeit $10’s and $100 ? s presented as a function of rapidprint number and approximate

Munsell Value 51

Figure 6. Chromaticity data for three areas for counterfeit $20’s and

$50's presented in 1960 Uniform Color Space 52

Figure 7. Reflectance of measured spots on counterfeit $20’ s and $50’

presented as a function of rapidprint number and approximate

Munsell Value 53

Figure 8. Chromaticity data for three areas of genuine $10 's, $20 ’s $50's, and $100's presented in 1960 Uniform Color Space 58

Figure 9. Reflectance of measured spots on genuine bills presented as

a function of new number and Munsell Value 59

\

vii
Executive Summary

The overall goal of counterfeit deterrence is to make it more difficult for

counterfeit money to pass undetected as genuine currency. A first step toward

that goal is to determine what features, if any, of counterfeit U.S. dollar

currency are noticed by human observers. Counterfeit currency is a problem

presently accounting for around $7.8 million in circulation in 1983, with $64

million seized by the Secret Service before circulation. The advent of inexpensive color copiers is expected to have a noticeable impact on the extent of

future counterfeiting. As a result, it is important to determine what features

enable people, particularly those with no training in currency handling, to discriminate counterfeit bills from genuine bills.

The present study was designed to explore the question of what features people

notice about paper currency, as part of an on-going research effort by the

Bureau of Engraving and Printing (other research efforts have been directed

toward machine evaluation elsewhere). Two approaches were used to determine

human detection abilities. The first was a review of the research literature

on counterfeit document detection. The second was a pilot study in which

untrained people identified bills as counterfeit or genuine, and indicated the

features responsible for their decision. These features were related to physical measures of color and reflectance where possible.

The review of the literature uncovered relatively little research specifically

dealing with detection and identification of counterfeits, with one notable

exception. Professor Ivor Stillitz conducted 10 years of research on this

problem for the Bank of England. His research is reviewed in detail in the

present report, in terms of both the methodology used and the results reported.

Initially, Stillitz determined that people could discriminate very small

differences in color and printing depth and could identify counterfeits based on

them. When Stillitz assessed note features remembered by people, he found that

they remembered the Queen’s portrait, the denomination, and the presence of a signature. He found that obscuration of the portrait significantly decreased

people's ability to detect forgeries reliably. He also found that people's

expectations played a major role in finding forgeries - when they were told

that forgeries were present, they found them, even when all the notes were

genuine. In fact, when they received money in a cash transaction simulation,

they frequently did not even count it, much less detect the real forgeries

present. Despite this result, Stillitz found that in a sorting task, even if

people did not identify the forgeries accurately, they still spent significantly

more time examining them.

These results led Stillitz to the conclusion that counterfeit recognition

could be improved if people were forced to spend more time looking at the note,

particularly at the portrait. To accomplish this, he suggested that variations

in size, shape, and color should be eliminated between notes, and that the

portrait should serve as the primary indicator of denomination.

Stillitz' research is particularly relevant to U.S. paper currency because many

of the denomination cues common to British currency such as changes in color.

viii
size, and shape are not used. The portrait, on the other hand, does vary among

denominations. U.S. currency would be close to that recommended by Stillitz

for maximizing attention except for the placement of the denomination counters.

Their position at the four corners of the bill means that no other cue needs to

be used to determine denomination. A bill can be used simply by looking at one corner and ignoring the rest of the note, including the portrait and other

engravings

A pilot study was conducted to determine if people could discriminate counterfeit

U.S. paper currency from genuine currency when allowed to inspect the entire

front of the note. (This approach avoids the problems noted above in which

only the denomination counter is examined.) In the study, 21 people who had no specialized training in currency handling examined a set of 102 notes. Their

task was to identify each bill as counterfeit or genuine, and state which

features were responsible for their decision. At the end of the study, they

identified the portraits for common denominations. Physical measurements of

chromaticity and luminance were also made.

The results indicated that people identified about 77 percent of the bills

accurately. There was considerable variation between people with a range of 40

to 92 percent accuracy in identifying all bills. Four people identified all 22

counterfeits correctly, but only one person identified all genuine bills

accurately. Nobody identified all bills correctly. Two counterfeits proved

particularly difficult to identify, with errors by about half the observers on these bills.

Despite the similarity in percentage correct identification for the two types

of bills, many more comments were made about the counterfeits. Features of

counterfeit bills that people noted frequently included problems with the

portrait, the color, the contrast, the feel, and the overall detail. On the

other hand frequently occurring comments about genuine bills included OK, feels

wrong, irregular borders, and printing defects such as blotches and stray ink.

Comparison of differences in physical measures of chromaticity and luminance

tended to confirm that counterfeit bills had slightly different greens, darker

whites, and lighter blacks than genuine bills. Thus, the comment data generally

tended to confirm that counterfeit bills had slightly different greens, darker

whites, and lighter blacks than genuine bills. Thus, the comment data generally

tended to confirm the physical data. The portrait data proved somewhat surprising

in that people were only able to identify George Washington on the $1 with any

accuracy. Combined with the comment data, these data suggest that people

appeared to be more certain of what the quality of the portrait should be, than

of whose portrait should be on a specific denomination.

In conclusion, the data from the pilot study indicate that people can identify

many, but not all, counterfeits accurately. Some counterfeits are good enough

to fool most people. Accurate identification of counterfeits is further

complicated by the fact that when people are told to look for counterfeits,

they term many geniune bills as counterfeit, often because of real printing

flaws. Yet, the features noticed on counterfeit bills tend to be different -

ix
related more to portrait quality, color fidelity, degree of contrast, and feel.

As Stillitz had found, people appear to notice something about forgeries that

they do not notice about genuine bills, even though they may not use this

information to discriminate the two types of bills.

Results from the pilot study and Stillitz' research reinforce the need to

increase the amount of time that people spend looking at bills during currency

transactions. These results suggest strongly that further research should be

done to evaluate the position of the counter relative to the portrait. The

effectiveness of centering the portrait between two counters, while removing

the counters from the edges of the bill, should be evaluated. Conversely, the

effectiveness of increasing the amount of security engraving in the region of

the present counter location could also be assessed. In addition, the effects

of increasing familiarity with the portraits on all denominations should be

assessed. These two efforts should increase the time spent examining the bill

and increase awareness of its engraving quality.

The effectiveness of greater color variation on all notes must also be assessed.

Color combinations which are readily perceived by people, but poorly reproduced

by copiers should be evaluated. The effects of variation in li'ght source spectral

composition on the chosen color composition should also be assessed to ensure

that inadvertent color shifts do not occur under common light sources. The

feasibility of increasing printing depth should also be assessed since Stillitz

found that people are quite sensitive to the tactile quality of engraved notes.

Other suggestions for increasing the effectiveness of counterfeit deterrence

include decreasing the number of very worn bills in circulation to heighten

dissimilarity with counterfeits. People in the pilot study commented repeatedly

on the difficulty of discriminating genuine worn bills from deliberately worn

counterfeits

In conclusion, data from the pilot study and from Stillitz suggest that people

are capable of discriminating counterfeits, but that their ability could be

enhanced by some simple design improvements to the note. The changes could

increase the amount of time that people spend looking at bills, and thus improve

their chances of detecting counterfeits. The desirability of increasing time

spent examining currency must be balanced against time lost during currency

transactions, however. The cost of increasing inspection time must consider

the extent of counterfeiting.

x
1. Introduction

The Bureau of Engraving and Printing has made considerable efforts to design

and print bills that are difficult to counterfeit. The design features selected

affect the appearance of currency to a marked degree. Yet, although there is

much information about design features of genuine banknotes, relatively little

is known about the features of counterfeit notes that actually play a role in

distinguishing them from genuine notes. What do people notice about counterfeit notes? Can they distinguish them from genuine notes? What features do

they use to make this distinction?

The present report is an attempt to determine the noticeability of features of

counterfeit and genuine U.S. banknotes for human observers. Two separate

approaches are discussed. The first is a review of the research literature

on features of counterfeit money. The review summarizes an extensive body

of research on the perceptibility of British pound notes. The research on British banknotes is one of the most complete efforts to determine which features

of banknotes are noticed and how these features affect the discriminability of

forged notes. There does not appear to be comparable research for U.S. paper

money. In the second approach, data from a pilot study on the discriminability

of counterfeit and genuine U.S. dollar bills are presented along with physical

data on the variation in chromaticity and luminance of a selected set of

genuine and counterfeit dollars.

1.1 Information on Design Characteristics of Counterfeit Bills

Several reports on counterfeit currency were consulted to determine which

design features of counterfeit bills tend to vary. These sources also provide

general guidelines to the public about which features to look for in identifying

counterfeit bills. These guidelines are summarized here to give an introduction

to counterfeit money in general and to provide some background for discussing

the currency features that participants reported noticing during the pilot

study.

Baker (1980) noted the following critical features of bills:

The portrait should be life-like;

The background lines around- the picture should be unbroken;

The sawtooth marks around the seal should be very even;

The serial numbers should be firmly and evenly printed;

The criss-crossing lines in the scroll should be clear and unbroken;

The paper should be strong and of good quality with red and blue

threads.

The colors should be clear, and not muddy.

1
Harshe (1978) pointed out that use of the intaglio printing process in which

paper is essentially forced into the printing plate to pick up the printing ink

is very expensive so that counterfeiters avoid it. This process, however,

imparts a very life-like quality to the portrait because it creates a third

dimension or "depth" to the bill. This "depth" is impossible to create with

any other printing method, so that flat, lifeless portraits characterize most

counterfeits. A genuine note appears lifelike - the portrait stands out distinctly from the fine lines of the background. In a counterfeit, the background

is often too dark, with the portrait seeming to blend right into it. For genuine

bills, as noted earlier, the Treasury seal is the right color with even, clear,

and sharp saw-tooth points. In the border, the engraved lines are continuous,

clear and distinct. These lines are invariably broken and weak on counterfeits.

Harshe noted further that U.S. currency is printed with secret ink, which can rub

off, unlike the ink on photocopies.

Cooke (1972) pointed out that the borders of genuine bills are engraved with

geometric lathes, again to make counterfeiting more difficult. Hand-engraved

portraits, lettering, scroll work, and other intricate designs are used to

make counterfeit printing more difficult. These engraving features also increase

the appearance of sharp, high-quality printing. The serial numbers. Treasury

seal, and Federal Reserve Bank designation are overprinted, rather than engraved.

Blank areas are left around them to show the quality and consistency of the

paper.

Torres (1980) pointed out that most counterfeiters use an offset method of

printing, rather than intaglio. Only about 5 percent of the counterfeiters

use the more difficult and expensive intaglio process. Torres also pointed

out several cues for verifying the genuineness of a bill. These include distinctive paper (75 percent cotton and 25 percent linen); distinctive red and

blue fibers that can actually be pulled out of the paper; typographic printing

of seals and serial numbers so that they lie on the surface of the paper; and

intaglio printing of portrait, signature, series number and complete back.

Other features include a match between the Federal Reserve Number and the

corresponding letter of the alphabet and uniqueness of each serial number

within the same denomination for a given series. Torres pointed out further

that estimates of the dollar value of counterfeit bills in circulation ranged

from 2.8 million in 1974 to 3.8 million in 1976. Estimates for 1983 were

$7.8 million in circulation, with $64 million seized before circulation

(Washington Post, 1984). Estimates of the value of bills seized, but not

circulated, ranged from 39.2 million to 64 million during the same time

period. Estimates for 1983, were $7.8 million in circulation (Washington

Post, 1985). Cities with the greatest numbers of counterfeit bills in

circulation included New York, Miami, Los Angeles, Boston, and Chicago.

Torres noted further that counterfeiting is not a new problem in the U.S.,

as problems of counterfeited wampum were reported for American Indians. In

addition, between 1789 and 1841 as much as $4.4 million in counterfeit bills was in circulation. The problem of recognizing features of counterfeit money

is obviously not a new one, despite current advances in printing techniques.

The Secret Service published a document entitled "Know Your Money" (1983)

which also provides some helpful hints for recognizing counterfeit bills. In

2
addition to the points already discussed, the booklet notes that the hairline

of the image in the portrait should be distinct and stand out from the background. Furthermore, counterfeiters may take a bill of a low denomination,

bleach out the counter (denomination) information, and replace it with a higher

denomination, or they may simply cut out a higher denomination thus "raising"

the face value of a bill. Detecting these changes requires paying some attention to the design features of the banknote.

Andersen (1975) reviewed some of the characteristics of banknote printing. His

major focus was on the quality of banknote printing as a primary security

device for deterring counterfeiters. His report reviews security devices,

including the principles, techniques, and even the esthetics of security

graphics. As he put it, "The various components of the banknote, its ground

patterns, its lettering, pictures etcetera may be executed so that their qualities are evident and their visual effect characteristic in a way that differs

signficantly from those of other printed matters. And these qualities should,

even to the more or less ignorant, or at least uninformed, public be easily

recognizable so that imitations will 'look wrong' straight away, even at a casual glance" (Andersen, 1975, p. 9). The note may look simple and be easily

recognizable, yet contain printing of very high precision and detail that is

very difficult to reproduce. Andersen attributes most of the quality of the

printing to the engraving process, which allows for very fine unique details,

as well as for variations in the actual ink color itself. He notes that

(p.12-13) "Very small deviations from the original line and dot structure

count immensely to the forger's detriment. Such tiny changes play a far more

decisive role in the portrait likeness and in the facial expression than similar

changes in the lines and dots would do to the likeness between, say, two

representations of the same landscape." As a result, many countries have used

the portrait as the focal point for their currency.

A review of the literature on counterfeit currency recognition yielded relatively

little information, with one major exception. The Bank of England conducted

about 10 years of research on the perceptibility of features of banknotes—both

good and forged—under the supervision of Prof. Ivor Stillitz. This research

will be presented in detail to provide an idea of its depth and breadth, and

to provide a framework for the pilot study on U.S. currency discussed in this

report

1.2 Perception Research

In 1976, Stillitz prepared a summary report of his research on perceptibility

of banknote features, entitled "Studies in the Ergonomics of Banknote Design".

He began by noting the following problems in determining noticeable features:

1) Expectancy of finding a forged note is low; 2) Misconceptions exist —i.e.

presence of a thread or watermark (even if an obvious forgery) is taken as positive proof that the bill is "good"; and 3) People do not normally pay

close attention to features degraded by forgery.

As a result, Stillitz proposed a "Control Model" for understanding and improving

the process of forgery identification and note handling. This model is based

on three separate processes. The first process is that of prolongation.

3
Stillitz theorized that making denominations more difficult to discriminate

from each other would result in more attention being paid to their features.

The second is interference—by which Stillitz meant that cues used for

denomination identification should be particularly liable to degradation as

a result of forgery. The third is a hybrid approach in which a salient cue such as a number is used for denomination identification, but is placed in an area of the note particularly likely to show the effects of forgery (such as the portrait). Thus, in the hybrid approach, attention should be prolonged

for areas which are most likely to be poorly reproduced in a forgery.

Before developing the control model, Stillitz worked on a detection model of

currency feature identification. To support the development of this early

model, Stillitz conducted a series of experiments designed to determine which

features of notes are detected, and to assess the role of different sensory

modalities in detection. Thus, this research assessed the role of different

senses, such sight, touch, hearing and smell, in detecting forgeries in a series of 26 experiments. In the following section, the results of each

experiment will be discussed in turn.

1.3 Visual Capabilities

The first sensory modality that Stillitz investigated was that of vision. His

initial concern was to determine which areas are typically looked at on a note. In Experiment 1, Stillitz observed 33 transactions in 8 different locations at a store cash register (till). This indicated that notes were generally

placed face-up in the register, suggesting that features of the note's front were critical in extracting information about the bill (such as denomination).

It should be noted that the fronts of all British notes currently contain a portrait of the Queen on the right-hand side with a secondary portrait to the

left of the Queen and the watermark on the left-hand side. Denomination information is presented both as a number (to the right of the Queen) and as a word

(to the left of the Queen). Each denomination is shape and color-coded.

Although much of the British currency is still the same that Stillitz used,

there have been some design changes since his work was begun. In addition,

the ten shilling note which he used in at least one experiment has been withdrawn from circulation, and the one pound note is scheduled to be withdrawn

later in 1985. Nevertheless, Stillitz' first experiment provided some baseline

information about the way in which pound notes are typically stored (and possibly presented to customers). This information suggests further that it is

the front of the bill which is critical and which people place in a position

to examine.

In Experiment 2, Stillitz used an "eye camera" to assess free viewing of note

slides that were rear projected for 10 sec. He assessed fixation time for 3

observers, and determined that the most frequently observed areas of the note

(British pound) were the portrait (35%); denomination text (23%); and signature

(13%). In Experiment 3, he measured time to identify note denomination with 4

observers. The time required was almost too rapid to measure. In Experiment 4,

Stillitz conducted an eye camera study of forgery detection with 4 observers,

with unsatisfactory results, due to unanticipated equipment problems. In

4
Experiment 5, he assessed the time required to identify a note when presented

in different orientations using a tachistoscope. A tachistoscope is a device

for presenting visual stimuli which controls presentation time, lighting levels,

and size. Stimuli may be either pictures or slides, depending on the device

used. Using 8 groups of 2 observers each, he determined that a longer viewing

time was needed to identify 10 and 20 pounds notes than l's or 5's, when the

notes were presented in unfamiliar orientations, such as upside down or reversed.

In Experiment 6, Stillitz conducted an interview study to determine the

characteristics of 1, 5, 10, and 20 pound notes that people recalled. People

were also asked to draw a picture of a 1 pound note. Subjects were divided

into 3 categories: low income, high income, and experienced groups. There was

no effect of age or sex, but observers who typically handled large amounts of

money were slightly more accurate. Nevertheless, bank clerks did not stand

out in terms of the amount or quality of information recalled. Of the note features recalled, the portrait, denomination number, and signature were most

frequently mentioned. Recall for the Queen's presence was high, but low for

specific features of her portrait. Subjects were vague about the visual form

of the watermark, the location of the promisary clause (promise to redeem the

note at its face value), and the exact signature characteristics. They also

had less exact information about the design characteristics of larger denomination notes with 52 percent providing no information about 20 '

and even being

unsure of their color. Sixteen percent, however, did remember the Shakespeare

motif on the back of the 20' s.

At the conclusion of the first six experiments, Stillitz theorized that the

following causes were responsible for what observers noticed and remembered.

The first was the salience of the attribute—size, shape, color, portrait, and

possibly elements of the denomination and serial numbers. The second was the

relevance of the attribute to everyday use of the note—i.e. color as a denomination cue, along with size, shape and possibly serial number. The third

was the meaningfulness of the attribute—such as the verbal promisary clause,

the portrait of the Queen, the watermark and security thread—attributes

associated with the validity and worth of the note. In this, Stillitz noted

features of similarity versus discriminability in different denominations.

Elements true of only one denomination were poorly remembered, with recall

being better for the type of element, rather than the specific nature of the

element. Many of these conclusions grew out of the data from experiment 6,

which set the stage for much of Stillitz' later research and conclusions.

Experiment 6 will be discussed again, in the context of the specific sensory

modality assessed, since Stillitz recorded all features of the note mentioned,

including tactile, auditory, olfactory, and, of course, visual.

In Experiment 7, Stillitz attempted to assess features of visual recognition

memory, by cutting up pieces of 5 pound notes, and presenting these pieces to

the observers tachistoscopically. (In many of his experiments, Stillitz used

slides as stimuli, but in Experiment 7, he apparently used the actual cut-up

pieces of money themselves.) Using this procedure with pieces of notes, Stillitz

5
found that only the ”5'' and the "un" of "pound” were consistently identified

as belonging to British currency. In Experiment 8 , Stillitz found that presenting

the "5” without the characteristic geometric background removed the cue needed

to identify it as part of a banknote. He theorized that the geometric patterns

were identified as part of a note, even if not recognized exactly. Experiments

9, 10, and 11 dealt with recognizing portions of 5 pound notes. Successively

greater portions of a note were displayed. In Experiment 10, these portions

were shown to 4 groups of 5 observers each; one with a blurry filter, one a red filter, one a clear filter, and one with no filter. In 6 trials, increasingly

greater portions of the notes were shown for each condition. In those conditions

with color distortion, more time was required to see greater portions of the

note. Thirteen of 20 observers did not identify the note until the fifth or sixth trial. This experiment appeared to support the idea of limited capacity

to recognize nonverbal, non-numerical components as part of a banknote. In

Experiment 11, when observers were asked to identify note parts in the context

of other stimuli, Stillitz determined that exposure of the characteristic

geometric pattern, although small, could lead to correct identification of a 5 pound note. This suggested the possibility of a recognition memory for detail.

The next series of experiments dealt with observers' sensitivity to the color

of banknotes and to variations from the correct color. In Experiment 12, a paired comparison method was used to assess the perceived genuineness of

colors, both blues and greens. Seven notes were assessed: a real 1 pound

note, and three notes that were greener and three notes that were bluer.

Notes that were marginally too blue or too green were perceived as less than

genuine. In Experiment 13, estimation of the magnitude of color variations

indicated that observers were less sensitive to changes in green than in blue

1 pound notes. Experiment 14, on just noticeable differences in color (JND's),

using the method of constant stimuli with 16 observers, (8 for 1 pound notes,

and 8 for 5 pound notes), showed that the JND for 1 pound notes (in green) was slightly larger than one ink unit, while that for 5 pound notes (in blue) was slightly smaller than one ink unit.

Stillitz commented that this series of studies indicates that the average

remembered color of the one pound note closely corresponds to the average

color of the actual note. Furthermore, notes which are close to that color

have a high degree of acceptance, but notes that are too blue have a greater

effect on perceived genuineness than notes that are too green. Finally, observers are less sensitive to changes in green than in blue—at least for one pound notes. (Variations in color for the blue 5 pound note were not studied

to the same extent.) No colorimetric specifications were given for blue or green, as no measuring equipment was available. Rather, color was created by

mixing real note pigments by weight.

Stillitz theorized that the differences were smaller for blue because:

1) people are generally less sensitive to variations in green; 2) the more

blue in the ink color, the more similar it is to the 5 pound note; and

3) unique green may be more green than the green of the 1 pound note, so that

there may be greater tolerance for a green that is greener than the green of

6
Che note. Unique green is defined as a green which has no blue or yellow in

it, and is considered to be perceptually unique (Wyszecki and Stiles, 1967).

Stillitz provided no information on the apparent yellowness of the green colors

that he used. Nevertheless, this series of experiments indicated that people

could discriminate very small shifts in color away from the true note color,

at least for green 1 pound notes. Confirmation of Stillitz’ s results is given

in vision experiments by Wright (1969) and others which have found that

visual sensitivity is less for small differences around 540 nm (green) than

for differences around 490 nm (blue) or 600 nm (orange-red).

1 .4 Tactile Capabilities

In Experiment 6, Stillitz also recorded mention of tactile information related

to note recognition. There were few spontaneous mentions of the tactile properties of the notes, although the following comments were made: new notes were

seen as crisp, while old notes were perceived as "grubby" or "limp". Sixteen

percent of the observers indicated feeling the Queen's portrait, thread or embossed numbers, while 18 percent indicated that they could not feel the

print. Thirty percent of the observers commented that the paper was strong

and of good quality. Stillitz commented that the recall for the intaglio

properties of the printing appeared low, and often misconceived.

In Experiment 15 Stillitz asked observers to identify notes by feel. He had

68 blindfolded observers separate notes from non-notes, by passing a note from

the non-dominant hand to the dominant hand, and then rubbing the thumb across

the note twice and putting it down. This imposed a time restriction. A total

of 24 stimuli were used in the following categories: new plate-printed paper;

old notes; new unprinted paper; and old unprinted paper. The paper was banknote paper and commercially available non-banknote paper in a variety of

qualities. The results indicated that "notes" made of new, uncrumpled Nelsondesign plate-printed banknote paper were accepted at a comparable rate to

genuine banknotes. Unprinted banknote paper that was made "old" had a high

rate of acceptance, as did old "Croxley Script" (a commercially available

paper that is favored by forgers). Stillitz suggested that oldness and

crumpledness decreases the rate of accurate recognition of banknotes. In

Experiment 16, Stillitz decreased the acceptability of old Croxley script by

using as participants, 48 male members of the general public (as opposed to

students). These people were presumably more experienced with money handling.

In this experiment, the acceptability of the plate printed note also decreased.

In Experiment 17, no restrictions on the length of time that the "note" was

felt were imposed for 16 observers. This change decreased the acceptability

of the Croxley paper from 87 percent to 31 percent. Finally, in Experiment 18,

with members of the general public, Stillitz found that if prolonged tactile

inspection were allowed, not one bank cashier or experienced observer accepted

the Croxley script. In each of this series of experiments, a slight order

effect was observed, such that forgery paper was more acceptable if it were

the first in the series of papers experienced.

Stillitz concluded that use of plate printing and bank paper contributes

substantially to the perceived tactile genuineness of a note, if it is new.

7
The acceptance of "old" forged notes is greater if people have not recently

handled genuine notes.

In Experiments 19 and 20, Stillitz experimented with the heaviness of the

plate printing, and mixed experimentally printed (but genuine) notes with

forgeries. Twelve blindfolded observers participated in Experiment 19, which

indicated problems with identifying aged, good notes as genuine. The results

in Experiment 20 were inconclusive, with problems of adaptation emerging.

Finally, in Experiment 21 Stillitz varied the depth of the plate printing,

using 2, 4, and 6 thous, (a measurement of printing depth) as well as plain

paper (which has little if any depth in printing). Genuine notes which are printed at a depth of 2.5 thous were also included. Eight observers made

paired comparisons to indicate which note of the pair was more genuine. From

this, Stillitz developed a scale of genuineness. He found that the probability

of acceptance decreased as the note deviated from "normal” thickness. The

same stimuli, along with a genuine 1 pound note were used in Experiment 22.

Eight observers indicated the genuineness of this set of notes. The results

indicated that the real note was seen as marginally more genuine than even the

2 thou note. Stillitz suggests that these results indicate a real capacity

for recognizing changes in depth of printing. In Experiment 23 he did a study

of the magnitude estimation of plate printing, developing a scale of perceived

"roughness" or "bumpiness" as a function of the depth of the plate printing.

He found that the perceived roughness increased with the depth of the printing,

but in less than proportionate fashion. Finally, he assessed JND's in plate

printing with 3 observers, and found that a JND was much less than 2 thou, and

that observers had total accuracy on this discrimination.

Based on the series of experiments on tactile discrimination, Stillitz suggested

that there appears to be a high degree of sensitivity to variations in plate

printing depth. In addition, people appear to have good short-term recognition

memory for the special properties of new banknotes. This suggests that tactual

properties of forgeries should facilitate, though not necessarily generate,

the occurrence of a "something wrong" response. Conversely, genuine notes

should facilitate a "something right" response.

1.5 Olfactory and Auditory Capabilities

Having assessed observers’ recognition, identification, and discrimination

capabilities for notes varying in visual and tactile qualitites, Stillitz

turned to a consideration of olfactory and auditory qualities that might aid

in discriminating good notes from forgeries. In Experiment 6, he had determined

that observers reported that new notes have a characteristic, but undefined

smell, while old notes do not have such a smell. In addition, observers had

indicated that new notes crackle, or have a characteristic sound when crumpled.

Stillitz tested observers' ability to discriminate notes on the basis of only

smell or sound in experiments 25 and 26. In Experiment 25, 24 observers were

tested on their ability to discriminate banknotes from newspaper and printed

glossy paper by smell alone. Subjects were not able to make such a discrimination accurately. In Experiment 26, 24 observers were asked to listen to a variety of papers being crumpled, and identify those that were genuine. There

was no evidence of any ability to identify genuine bills by sound alone.

8
1.6 Expectations

In the previous series of experiments, Stillitz determined that visual and

tactile cues were useful in discriminating forgeries from genuine notes.

These cues are most useful, however, to people who are looking for forgeries.

Stillitz turned next to a consideration of the role of expectations in

determining forgery detection. In the next series of experiments, Stillitz

investigated observers’ knowledge and expectations about forgeries. In

Experiment 27 , he reviewed witness statements about forgeries from forgery

trials involving 30 cases with six witnesses and 5 types of forgery. A content

analysis of witness statements indicated that they typically mentioned one to

three features of forgeries. These generally included general appearance,

degradation in color or tone, and problems with thread, serial numbers and

feel or texture. Although this approach would appear valuable, the problem

was that the witness statements were highly stereotyped, with indications of

police prompting, so that these data may not reflect what the person-in-thestreet would notice.

In Experiment 6, observers had been asked what they would look for in detecting

a forged note. They mentioned the security thread, watermark, serial number

agreement, comparison with other notes, feel/material, and design quality.

Design quality responses indicated the following characteristics of forgeries:

poor quality of printing; blurred writing; writing defects; something wrong

with design; and something missing or out of place or proportion. At least

3/4 of the observers stated characteristics likely to identify good quality

forgeries.

After evaluating people’s expectations about forgeries, Stillitz turned to a determination of whether observers could identify forgeries in a set of mixed

genuine and forged notes. The first step was to determine their expectations

about forgeries — would they find forgeries among genuine notes simply because

they had been told that forgeries were present? Thus, in Experiment 28 observers

were asked to pick out forgeries from a set made up of genuine notes only.

The set consisted of 30 one pound notes which varied in wear. Thirty-one

percent of the notes were identified as forged, with many observers reporting

judgements based on objective variability in the notes. They relied primarily

on five features: thread, feel of note, color, watermark, and the Queen’s

portrait. (Responses about the thread were related to its position on the

note, rather than its presence or absence.) Stillitz noted that if people are convinced that forgeries are present, they will reliably find forgery attributes

in genuine notes. They appear to be aware of the direction of forgery degradation, but their idea of the limits that distinguish forgeries from genuine

notes is poor.

In Experiment 29, observers were asked to detect forgeries in a series of

slides presenting genuine and forged notes. The slide was exposed for 200

msec every 3-1/2 sec. Subjects pressed one of six keys indicating the following

categories: certain forgery, fairly sure forgery, guess forgery, guess genuine,

fairly sure genuine, genuine. Twelve forgeries of one pound notes were used

with a quality ranging from very good to very poor. Forty-eight slides were

9
created from these forgeries. A total of 96 slides was used—48 forgeries and

48 genuine notes—with 15 observers. Under these conditions, forgeries were

detected and categorized appropriately. Furthermore, the category ratings

given by "untrained” observers for the forgeries were highly consistent with

the rating of the quality of each forgery given by Bank of England experts,

with no genuine notes taken as forgeries. The attributes of forgeries which

led to detection were: 1) Imperfections in color; 2) imperfections in

definition; and 3) imperfections in tonal range, with 2 and 3 being marginally

more important.

These results led Stillitz to the next experiment (30) on the effect of

variations in definition and tonal range on the detectability of forgeries

when portions of the note are obscured. He obscured the portrait and other

randomly chosen areas, and found that obscuring any part of the note led to a drop in the observer's sensitivity to differences between real and forged

notes. The drop in performance was greatest when the portrait area was obscured.

Stillitz suggested that the tonal range and/or the quality of fine plate printing

may be particularly important in deterring forgeries. For example, people may

be especially sensitive to the precise nature of the facial expression in

familiar portraits.

In Experiment 31 Stillitz used a more realistic situation in which actual

forgeries and genuine notes were sorted. He used 20 five pound notes, 53 one pound notes, and 12 forged one pound notes presented in a predetermined random

order with the best forgeries first and the worst ones last. This was done to

avoid alerting observers to the presence of obvious forgeries. Ten observers

sorted the wad of notes into piles of one and of five pound notes. The idea

was to determine if forgery detection would spontaneously occur. No observer,

however, made any spontaneous comments, but on debriefing 9 of 10 observers

indicated that they believed some of the notes were not genuine, and suggested

that about 3 to 6 notes had actually been forgeries. The sorting procedure

had also been filmed. Subsequent analysis of the film indicated that observers

actually took longer to analyze the forged notes than the genuine notes. This

time was longer for all forgeries—even the "good ones"—with the data suggesting

that some kind of mental "double-take" was occurring. (Evidently, analysis of

the film was unable to indicate what the observers were doing that took more

time—just that the process took longer.)

In Experiment 32, observers were again asked to sort money by denomination,

with the pile of money including both forgeries and genuine notes. In this

study, 7 observers received the "best" forgeries first, while 12 observers

received the "worst" forgeries first. This time, they were asked to sort the

money into 3 piles: one pound notes, five pound notes, and defective notes

(with defective being left unspecified.) Observers again took longer to sort

the forgeries. For the first group of observers, 7-8 of the 12 forgeries were

rejected (as defective), with observers indicating when debriefed that they

had rejected anywhere between 0 and 14 notes. The results were similar to the

slide experiment. Experiment 29, with the rejection rate for the forgeries

about the same, and an indication that the worse the forgery, the more likely

it was to be rejected. For both experiments, it took longer for the observers

to sort the forged notes, even if they were judged to be genuine.

10
In Experiment 33 , a more detailed assessment was made of the time to accept

and reject forgeries. This experiment was a reaction time experiment, in

which observers sorted notes into the three categories given above by pressing

the appropriate key. The "time to decide," and "accuracy of the decision"

were measured. There was a high correlation between the number of times a forgery was rejected and the rating of the quality of the forgery given by

the Bank. Time to accept forgeries was longer that needed than to accept

genuine notes. "Time to accept" forgeries decreased, however, when the quality

of the forgery increased, but "time to reject" increased for good forgeries.

(This implies that it is easier to decide about relatively bad forgeries than

good ones, and that this decision time can be measured objectively.) In this

experiment, some good notes were rejected as forgeries, but with a longer

reaction time than when the good notes were accepted as genuine.

In Experiment 34, Stillitz studied forgery rejection in a role playing situation.

He had observers make out a check for 30 pounds and cash it, with the experimenter serving as teller. Six observers received 6 forgeries in their money,

while 9 observers received only 1. A major problem was that not all observers

counted their money. Of the 4 observers who counted the money, one found no forgeries, one found 1 forgery, and two found 5 forgeries (out of 6). These

data suggest that people do not typically inspect each note they receive, and

further, that only a minority, even when inspecting, notice quite poor forgeries.

Finally, observers noticed forgeries more when more forgeries were included in

the packet of money. In Experiment 35 the roles were reversed with the observer

now serving as the teller, counting out the notes given in response to the

check. There was a much lower rate of forgery detection in this situation.

These data suggest that peoples’ expectations of finding forgeries can be

manipulated. If they expect to find forgeries, they will classify some genuine

notes as forged (see Experiment 28). Yet, if they do not expect forgeries,

they may not even inspect individual bills when given a handful of currency.

The problem of manipulating expectations will be discussed further in the

discussion of the pilot study results.

In reviewing the results for experiments 28-34, Stillitz made the following

important points: I) people's sensitivity to different forgeries, when presented

visually, is highly correlated with the Bank's estimates of quality; 2) people

rarely judge a good forgery to be as good as a genuine note, even if they

think it is genuine; 3) the portrait area appears to have special value as a security device; 4) there does not appear to be any fundamental sensory limitation on the capacity to detect forgeries (with the suggestion that there are some sort of subliminal registrations occurring); and 5) in role playing situations, the probability of noticing something wrong with the forgery is lowest

if only one forgery is included with many genuine notes.

Following the preceding series of studies, Stillitz developed his original

detection model into a control model. The detection model had focused on the

sensory cues used by observers to identify bills and bill characteristics.

Central to the control model, however, is the idea that people's detection of

important banknote features can be controlled, thus allowing more time to be

11
spent in the process, and increasing the likelihood of detecting forgeries.

His research suggested that the denomination color and numbers were especially

important, with recognition memory for detailed features being particularly

poor. People appear to have a great capacity for tactile recognition, indicating that high plate printing (which creates depth on the note itself) might be

valuable. (The only problem would be wear over time.) Stillitz found no evidence that people can recognize notes by smell or sound alone.

Stillitz suggested that a control model could be used to design currency with

greater sensitivity to forgeries by increasing the value of specific security

features. His central assumption was that information relevant to the identification of the note denomination is always processed and analyzed. The current

state of British currency is that there are a multiplicity of highly obtrusive

cues to indicate denomination. These relevant redundant cues (RRC'S) include:

number, color, size, portrait, and general design. If discrimination time

could be prolonged, then it might be possible to force people to pay attention

to the engraving quality and other security features. Stillitz suggested that

a parallel process was occurring, in which people matched the general features

of a note to their expectancies of what a note should look and feel like.

Thus, successful detection of forgeries requires the following: increase the

probability of the "something wrong" response; (this probability is increased

if more time must be spent inspecting the note); increase time spent by

decreasing between-denomination cues (reduce relevant redundant cues and thus

lower salience); and relate the probability of forgery detection to the time

spent to discriminate the note denomination.

Stillitz used the control model as the basis for designing the next series of

experiments. In Experiment 36, he conducted a card sorting study which assessed

the value of 4 cues—color, shape, denomination number, and denomination text.

He measured the discrimination time as the number of RRC's decreased; and the

relative potency of the 4 selected cues when presented in isolation. Stimuli were cards representing 1 and 2 pound notes, with specific cues for each denomination. One pound notes were represented by one or more of the following:

green, rectangular, 1, and ONE; while 2 pound notes were represented by: blue,

square, 2, and TOO. There were 32 sorting conditions for the experiment plus

two extras: 1) observers sorted blank cards into two piles to provide a baseline

measure as well as some practice; and 2) observers sorted cards with inappropriate cues (such as 1, TWO) to provide a measure of the effects of distraction.

Each card in the main experiment could have from 1-4 cues for denomination.

Subjects then sorted the cards into two piles. Stillitz found that discrimination time decreased systematically as the number of RRC's increased from 0 to

3 (4 cues on card), with the time for 3 RRC's about 80 percent of that for no RRC's. The greatest reduction in time occurred between 0 and 1 RRC. The most

efficient cues, with the quickest discrimination, were color and numeral (about

equal) with numerical text next, and shape last.

With no redundant cues, numerals were somewhat more efficient than color, but

with redundant cues, color appeared to be superior. Stillitz suggested that

these results indicate that the number of relevant redundant cues can safely

be reduced. (It is interesting to note that US currency has a greatly reduced

number of RRC's compared with British. There are no color or size cues —rather

the cues for denomination are numerical and design only.)

12
In Experiment 37, Stillitz conducted a preliminary test of the prolongation

hypothesis. He used notes of two denominations as well as forgeries, and

presented pairs of notes to four groups of 9 observers each. The discriminability of the genuine note was deliberately varied by changing the number of

RRC's included on it. Stillitz hypothesized that the probability of forgery

detection would increase as the discriminability of the genuine note decreased.

In one condition he removed the lower left denomination guilloche (an engraved

design embellishment), while in another he presented 10 shilling notes in the

color of the one pound note. Four forgeries, varying in quality, were used.

He found that observers were better at detecting forgeries when the guilloche

had been removed from the genuine note, than when it was presented in the

wrong color. They were also better at detecting poor forgeries, and got better

as the number of redundant cues (RRC's) in the genuine notes were reduced.

There was no indication of increasing confusion between the two genuine notes

for the various cue change conditions.

In Experiment 38, Stillitz did a more thorough test of the prolongation

hypothesis with a set of 128 slides of specially designed experimental notes.

To create this series of slides, Stillitz used both 1 and 5 pound notes, and

used 5 pairs of notes with varied elements. These differed in shape, size,

color, denomination text, and numerals. He also created "forgeries" of each

special note by: 1) altering the color value by changing the camera stop; and

2) photographing the note through gray mesh, which degraded the sharpness, and

altered the color value slightly. A total of 40 observers participated in the

study. Unfortunately, the results were inconclusive because the backgrounds

were varied inadvertently for some of the forgeries. As a result, the experiment was repeated with masked backgounds (Experiment 39). Stillitz found that

the reaction time was longer (about 2 sec) for stimuli with five redundant

cues. It was shorter (about 1/2 sec) if there were no forgeries among the

stimuli. In Experiment 40 he assessed discrimination time for the different

genuine notes only (no forgeries presented). He found that as the note design

similarity increased between the two notes, reaction time increased slightly.

Thus, in condition 5 the two denominations were very similar in size, shape,

color, format, and orientation. They differed only in denomination text and

numbers, with the portrait's left ear visible on the one pound note, but not

on the five. In condition 1, everything differed. Stillitz found generally

that the predictions of the prolongation hypothesis were not verified with

statistical significance. Although the trend was in the right direction, the

effect was small compared with the variability between observers.

In Experiments 36 through 40, Stillitz observed the effects of varying the

number of salient cues on banknotes with a set of specially designed notes.

He found that he could control the amount of time needed to identify a note

depending on the number of cues for denomination presented. The results were

most conclusive when people were asked to discriminate genuine notes from

forgeries (even when the "genuine" notes had been specially designed for the

study and were not in general circulation). The results were less conclusive

for situations in which people were asked simply to discriminate between two

genuine notes. Nevertheless, this series of studies left Stillitz with the

conviction that the number of cues on a banknote is a critical feature in

13
controlling the amount of time spent inspecting it (and thus providing an opportunity for detecting counterfeited notes).

In "A Review of Perception Research" (1978-1979), Stillitz reviewed a later

series of studies intended to delineate further the role of perception in the

noticeability of features of notes. Since this review provided much less

detail about the experimental procedures followed in the research, only the

results will be discussed here.

In this series of studies, Stillitz explored stimuli similar to the control

notes discussed earlier. At this time, he focused on variations in the actual

design of the notes, particularly the portrait and color. His stimuli included

variations in note design such as: numeric notes; hybrid notes; the "green"

Queen (in which portraits for different denominations differed in color as well as in design); and hybrid notes in which the placement of the numeral

varied relative to the portrait. Results with the original hybrid notes indicated that placing the numeral next to the portrait masked the portrait. Use

of an improved hybrid note indicated that people are sensitive to changes in

expression and color of the portrait, but that numeral position can affect the

noticeability of the portrait. Typically, reaction time or accuracy of identification were used as response measures. Based on results with these various

designs, Stillitz suggested that each denomination should be characterized by

a different portrait and that the numerals should be low in salience (or

attention-getting power). He found that placement of the numeral to minimize

its salience created some difficulties, because when a single one was placed

near the portrait it tended to mask the portrait. If it were placed too far

away, people tended not to look at the portrait, so that its special engraving

qualities were overlooked. Stillitz suggested that if color differences between

portrait and numeral were maintained, then perhaps the numeral could be placed

close to the portrait.

Stillitz also tried to conduct a series of eye camera studies to assess which

features of the note people examined. The studies were an attempt to determine

whether the denomination color should cover a greater part of the note’s surface

or be restricted to a limited portion. Despite the promise of this approach,

this series of studies produced inconclusive results due to equipment problems.

In another, more informal study, Stillitz observed 200 note-handling events in

6 busy stores. He noted that notes were stored flat; that they were typically

unfolded and presented flat to the cashier; and the location of the notes in the

cash register served as an important cue. Notes currently appear to be sorted

by color and size.

In another report, Stillitz discussed the potential advantages and disadvantages

to special security devices contained in the banknote to discourage forgery.

(For U.S. currency such devices currently include the red and blue threads,

while for many European currencies, these devices include a watermark and a metallic security thread.) Stillitz noted that special security devices are intended to be as a deterrent to forgers. They can be held in reserve for

addition to the currency at short notice. Along with these special additions

to the banknote, the security devices can also be qualitative, such as the

14
overall clarity of the print on the note or the lifelike expression of the

portrait. Such devices are often overlooked because they are used so frequently,

but as Andersen (1975) pointed out, they can be some of the most effective

deterrents for everyday use. One feature of specially added security devices

is that they can be used as absolute indicators of the genuine nature of the

note or bill. A drawback to this use is that if the device is present, however

poorly reproduced, its presence may be taken as certainty that the bill is

genuine, even if its engraving qualities are so poor as to be laughable. As a result, decisions about the genuineness of a note may be made on the presence

or absence of a special security devices, rather than on its perceived validity.

Thus a very poor counterfeit may be accepted simply because it has a security

thread, watermark, or other recognized security device. Stillitz commented

that high quality printing suggests genuineness while the presence of security

devices, however, poorly done tends to confirm genuineness. A successful

simulation of a special security device can be very deceptive, as people may

check only for its presence and not for other engraved characteristics of the

note. In addition, the special devices now are in the paper itself and may

not be noticed in actual practice.

Stillitz commented on several areas in which further research on banknote

design and perceptibility is needed. These areas include: need for better

evaluation techniques; determination of the perceived relationship between the

back of the note to the front; assessment of the effects of security devices

in counterfeit bill detection; and evaluation of the effects of variation in

factors such as design content outside the portrait area, numerical location,

size, and shape. Because there is a problem with numerals near the portrait

which tend to mask the portrait and compete for attention, one might manipulate

the relative salience of the numeral and the portrait to study the masking

effect. The masking effect could decrease as the salience of the numeral

relative to the portrait decreases.

1.7 Recommendations for Banknote Design

Although there is a need for further research on the effects of specific design

variations on banknote salience, the results from this series of experiments,

combined with the earlier experimental data were strong enough to allow Stillitz

to draw some useful conclusions about banknote design. Stillitz recommended

that: notes should all be the same size and shape; they should not differ

only in color; differences in major features should be minimized; denominations

should not be totally dissimilar; overall shape should not be the cue; and

attention to denomination should be maximized. Stillitz suggested that the

portrait is a most valuable device for presenting the quality of the banknote

since some of the best engraving is used to create the portrait.

Stillitz noted that a number of questions remained unanswered in his research.

The qualities needed in the second portrait on the front of the note remained

unclear, as did the relationship of the back of the note to the front. In

particular, the role of a vignette for the second portrait was not defined,

along with the need for portraits of people in this area. Although geometric ' abstract material can lack memorability, it may be important in indicating

15
value and worth. In fact, notes appear to require handwork and pictorial

matter to indicate worth. The use of several colors is appropriate, but they

should be chosen so that the juxtaposition of colors makes degradation more

noticeable, and enhances contrast. The eye’s ability to make fine color

discriminations should be used to greater advantage.

Based on ten years of research on the perceptibility of banknotes Stillitz was

able to generalize about the design characteristics which appear to increase

the likelihood that a forgery will be noticed. He provided the following

guidelines

1) Make the back and the front of the note equally difficult to forge.

2) Make portraits the same color, but use different people.

3) Use distinctive characteristics for note fronts and backs. They should

differ by conceptual cues such as historical age or relation to British

Royal Family.

4) Do not vary color outside the portrait area between denominations. The

general color pattern of the backs of the denominations should be different

from the fronts.

5) Features other than the portrait which indicate denomination or side of

the bill should have low salience.

6) Make the general impression of the color the same.

7) Do not use lithography and plate printing to create the same kinds of design

elements, as their quality differs, and may create the impression of forgery

when used in the same place.

Other discussions were related to design content. Stillitz made the following

suggestions

1) Use a representational form with expression or atmosphere. This shows the

qualities of banknote printing.

2) Use few visual elements. These should be simple and delineated.

3) Use design content (including geometrical work) to link portraits.

4) Make the public aware of the theme of the banknote.

5) Define the desirable properties of the note content through basic and

applied research.

6) Use the numeral and denomination text as secondary targets to focus attention on the printing quality.

16
1.8 Relevance of Stillitz’ Research to U.S. Currency

Stillitz’ work suggests a number of ideas which are relevant to the design and

evaluation of U.S. currency. First, there is probably little need to do further

work on olfactory or auditory cues for detecting forged or counterfeit money.

Second, people have the ability to make very fine tactile and color discriminations not only in a psychophysical laboratory study, but also with actual

currency. There is ’’something” people notice about forged notes. For some,

as-yet unclear reason, it takes longer to make decisions about forged notes —

even decisions as easy as sorting notes by denominations. Stillitz' later

research attempted to sort out the cues responsible for this difference. Even

though the studies were not definitive,, they point out the need to do multidimensional research, in which the input from more than one type of sensory

awareness is assessed.

Future work might usefully examine the interaction of color, line quality,

and feel in contributing to the sucessful detection of forged banknotes. In

this approach, the role of acoustical and olfactory cues could conceivably

become more important, even though in isolation these cues appear relatively

ineffective. It is more likely, however, that the effectiveness of those cues shown to be effective in isolation, namely, color, overall appearance, and

tactile quality, might be increased.

This tack certainly appears to be the approach followed by Stillitz. His work

with the control model and the hybrid notes strongly supports the attentiongetting value of the portrait, although it only begins to suggest why this occurs. His research also indicates that it is possible to manipulate the

ability to discriminate both in speed and in accuracy between different denominations by varying the number of cues on a note (such as color, size, and

graphic characteristics). This manipulation is also sucessful in altering the

recognizability of "forgeries” designed from such hybrid notes. In sum,

Stillitz’ research points out that it is possible to vary the detectability of

forgeries by varying the design quality of "genuine” notes. The most successful variations appear to be related to the color, portrait, placement of the

counter, printing depth, and number of denomination cues on each bill.

Any body of research that is as comprehensive as that conducted by Stillitz

will necessarily have implications for the design and evaluation of other

currencies. Although Stillitz’ work was conducted with British pound notes,

primarily denominations of ones and fives, it is useful to assess its relevance

to the noticeability of counterfeited American dollars.

In the following sections of the present report, a pilot study on the

noticeability of U.S. dollar notes is discussed. This study bears some resemblance to a number of Stillitz’ studies. Where common results occurred, they

will be pointed out. Physical measurements of the chromaticity and luminance

of a set of counterfeit bills are also presented to provide an indication of

the variability to be expected. Finally, Stillitz ' recommendations are reviewed

for their relevance to U.S. banknote design.

17
2. Approach

2.1 Stimulus Material

A set of 108 counterfeit U.S. dollar notes was obtained from the Secret Service.

The Secret Service had seized these bills in New York, Miami, and Los Angeles,

(cities which have a large number of counterfeits in circulation), in 1982.

An attempt was made to get as many different types of bills as possible, in

the following denominations: $10, 20, 50, and 100, since these are counterfeited far more frequently than $1 or $5's. (In fact, the final sample con- tained relatively few $10’s.) All bills had been in circulation when they

were seized. They were stamped "counterfeit," on both sides, although some

bills did not have "Counterfeit" stamped on the front. These later bills were

selected, since they were to be used in a pilot study in which genuine currency

was to be discriminated from counterfeit bills. Throughout the following

discussion, all bills are identified by the last four digits of their serial

number, denomination, and category (genuine or counterfeit).

All the counterfeit bills were then measured with a spectroradiometer to

determine the extent of variation in chromaticity and reflectance in 6-8

locations on the bill. Spectral measurements were made with a telescopic

spectroradiometer. Illumination was provided by a source developed especially

for this purpose, consisting of a small 12-volt spotlight with a piece of

diffusing plastic in front of it. This light was powered by a voltage-regulated

DC source, and mounted directly above the spot being measured. The exact

position of the light source was chosen and controlled to minimize random

errors. The light source itself had a chromaticity of about (x, y) = (0.453,

0.419) or (u, v) = (0.254, 0.353). While light was incident along the normal

to the spot measured, the spectroradiometer was aimed at 45 degrees from the

normal, so that the spectral measurements had a 0°-45° geometry. For practical

purposes, this means that the specular component of reflectance was excluded,

and the inks were seen at their blackest and most saturated. The spectroradiometer was positioned and focused to measure a spot about one mm in diameter

(elongated on the banknote because of the 45° viewing angle). The 1-mm spot

size can be considered "quite small" and is much smaller than could be achieved

with older techniques; nonetheless, the measurements which are termed "green

seal" and "black letter" many involve some variable incursion of the un-inked

paper into the measurement spot.

All measures were made relative to a reflectance standard with a luminance of

about 695 fL. These included: the back lathework near counter upper right;

the front lathework near counter, in the upper right; the white area on the

front near the serial number (without the back of the bill showing through);

the green seal; the right center background area of the portrait; the black of

the Federal Reserve Bank letter; the green seal plus black lines; and the

white area near the seal plus black lines. Only one measure of the back of

the bill was taken—all other measures were of the front. (Additional measures

were taken of the seal area because it appeared that the dark areas of the

denomination text were darker on counterfeits than on genuine bills.) Similar

measures were taken for a limited set of genuine bills, as well.

18
The spectroradiometric measures were converted to CIE chromaticity coordinates

and then graphed in the 1960 Uniform Color Space (uv) to provide an indication

of the variability in counterfeit bills.

The CIE chromaticity system provides a means for specifying color using three

primaries or "tristimulus" values. The three tristimulus values are discussed

from color matching data of a "Standard Observer" (Wyszecki and Stiles, 1967).

Because the three tristimulus values must sum to one, it is possible to determine

two values, x and y by convention, and derive the third mathematically. As a result, the CIE chromaticity diagram is a two-dimensional diagram on which the

x and y coordinates are plotted. These two coordinates specify the amount of

red (x) and green (y) in a match. Unfortunately, the CIE x,y system does not

represent all perceptual differences between colors accurately. Uniform color

systems such as the u,v system used here, were developed to allow one to plot

color differences as they would be seen. Thus, differences of the same units

between two sets of colors should be perceived as equal in u,v system but may

not be in the x,y system. As a result, the u,v system was chosen to demonstrate

differences between measured chromaticities of counterfeit and genuine bills.

Measures of luminance were converted to Munsell Value units to provide an indication of reflectance. Munsell Value was used to represent the reflectance

of bills. The Munsell color system specifies colors with three dimensions —

hue, chroma (saturation), and value (lightness). Value represents the "lightness"

of a particular color. The Munsell system is another system developed to

allow ordering of colors in a perceptually meaningful manner. Value units

thus represent differences in lightness which can be perceived.

2.2 Pilot Study Design

The pilot study was designed to be an initial assessment of the discriminability

of counterfeit currency when mixed with genuine currency. It was intended to

provide some baseline data of the ability to select counterfeits from genuine

bills, and to provide an idea of some of the reasons underlying this

discrimination.

A set of 80 genuine bills was obtained from the Bureau of Engraving and Printing.

Four denominations were used—10, 20, 50, and 100 —in three wear categories

good, bad, and very bad. Wear category was determined prior to the experiment

by the Bureau of Engraving and Printing. A set of 22 counterfeits was selected

from the larger set of counterfeits described previously. This set included 3 $10's, 6 $20’s, 6 $50's, and 7 $100’s. These bills were selected to represent

a range of wear, as well as to minimize obvious indicators of counterf eitedness

A total of 102 bills were used in the study. These bills were randomly divided

into 3 groups of 34 bills each, simply to give each participant several stacks of

money such as might normally be experienced during money counting.

During the pilot study, each observer was brought individually into the NBS

Illumination Color Laboratory. Light levels were maintained at about 40 fc

(36 fl). Illumination was provided by cool white fluorescent tubes, located

about 2.5 m above the viewing surface. The surface itself was a piece of

light grey cardboard located on a table. The observer was seated in front of

19
this table and given the instructions (see table 1 of the Appendix). During

this time, the experimenter randomized the bills in each of the three stacks.

The very first bill was deliberately selected to be a very poor counterfeit so that people would be somewhat familiarized with counterfeits. This procedure

was adopted after one of the first observers identified the majority of bills

as counterfeit. After completion of data collection with this person, the

procedure was changed to provide some initial, informal familiarization with a noticeably poor counterfeit bill.

Each participants selected one bill at a time, decided if it were good or counterfeit, and if he or she were sure or unsure of the decision. Viewing time

was limited to about 10 sec. Participants then handed the bill to the

experimenter and gave the reasons for their decision. No time restrictions

were imposed on their comments. The experimenter recorded each decision and

comment. Since only one bill was in view at a time, a participant could not

compare bills with each other. The experimenter did not provide any feedback

about the judgements, either, although reassurance was provided that people

were doing fine. At the end of each of the three stacks of bills, the

observer was given a chance to rest. The whole process took about 1 to 1-1/2

hours, depending on the observer. (Some observers made many comments about

every bill —others made relatively few.)

A total of 21 people participated - 13 males and 8 females. The participants

included 9 professionals, 5 secretaries, 2 technicians, 3 students, and 2 housewives. Two of the participants were color defective (as determined by

the American Optical H-R-R color vision plates), but no other vision problems

were reported. All participants were volunteers, with no specialized training

in currency handling.

After participants had viewed all the bills, they provided general comments

about the features that they noticed, the importance of these features in

their decision, and an indication of their experience with money handling in

general, and counterfeit bills in particular. They also named the person

whose portrait appeared on U.S. paper currency, including $1 and $5's as well

as the four denominations used in the pilot study. Finally, they were shown

several counterfeit and genuine bills and given a chance to compare them.

General guidelines as given by the Secret Service on spotting counterfeit

bills were also discussed.

2.3 Background—The Problem of Analyzing Detection Data

In the present study, participants examined notes that were a mixture

of genuine and counterfeit bills. Their task was to detect the

counterfeit bills in each stack of money. For each bill presented,

there were four possible responses:

1. The bill is a counterfeit and is correctly called counterfeit by the

subject. This is a "correct detection," or simply a "hit."

2. The bill is counterfeit but is called real by the subject. This is an incorrect rejection or a "miss."

20
3. The bill is not a counterfeit but the subject says it is. This is an incorrect detection, or simply a "false alarm."

4. The bill is not a counterfeit and is called not counterfeit by the

subject. This is a "correct rejection."

Problems of this type, concerning the detection of something that might or might not be there, have been studied extensively under the heading of "Theory

of Signal Detection" (TSD). TSD had its origin in the development of radar,

but has also been used to deal with detection of sounds and lights by humans

(see Jeffress, 1964). While the theory of signal detection will not be discussed

in detail here, some basic ideas from TSD can help to analyze the counterfeit

identification data and give insight into the whole problem of counterfeit

detection. The most basic of these ideas is that if the task is a hard one,

false alarms are unavoidable, and must be dealt with in the analysis.

When an observer is presented with a number of bills, each response falls into

one of the four categories, so that the result is a count of hits, a count of

misses, a count of false alarms, and a count of correct rejections. Simple

arithmetic imposes two constraints on these numbers, for

(no. hits) + (no. misses) = (no. counterfeits presented)

and

(no. false alarms) + (no. correct rejections) = (no. real bills presented).

Thus, only two of the four results are independent numbers. It is common to

define "hit rate" = (no. hits)/(no. counterfeits) and "miss rate" = (no. misses)/

(no. counterfeits). Also, "false alarm rate" = (no. false alarms )/(no. real bills)

and "correct rejection rate" = (no. correct re jections )/ (no . real bills). The

constraints imposed by arithmetic then become

hit rate + miss rate =1.0

false alarm rate + correct rejection rate =1.0

Hit rate and false alarm rate are usually taken to be the variables of interest,

with the other two rates implicit. Although the primary parameter of interest

is the observer’s "ability" to detect counterfeits, two numbers are obtained

that relate to this ability. The extra degree of freedom relates to the

observer's criterion . If the observer chooses (or is instructed) not to call

something a counterfeit unless he or she is really sure , then the hit rate and

the false alarm rate will both be low. If the subject chooses to accept as a counterfeit anything that looks minutely suspicious, then both the hit rate

and false alarm rate will both be higher. If the hit rate is equal to the

false alarm rate, this implies chance performance.

21
Regardless of criterion, the observer can show "ability" by giving a hit rate

greater than the false alarm rate. (Hit rate less than false alarm rate would

indicate ability compounded by a desire to give the wrong answer.) The effect

of criterion can be assessed by asking an observer to be more (or less) certain

that he/she has detected a counterfeit. A sequence of trials done by the same observer at several criterion levels would give a set of differing false alarm

rates, each with an associated hit rate.

A graph of hit rate versus false alarm rate from such an experiment is called

the "Receiver Operating Characteristic" or "ROC curve." It has the general

appearance of the upper graph in figure 1. While the data in this figure are hypothetical, the common features of all ROC curves are displayed:

1. The graph is square. The curve passes through (0,0) and (1,1), since

the strictest possible criterion would result in zero hits and zero false alarms, while the loosest criterion would be to press the button

on all trials.

2. The diagonal from (0,0) to (1,1) represents chance performance. That

is, hit rate = false alarm rate implies that the probability of the

observer's responding was independent of the presence of stimulus.

3. If the subject is making the best effort, the curve will rise monotonically from (0,0) and across the graph. That is, a loosening of the

criterion should increase both the hit rate and the false alarm rate.

Any deviation of data from this rule must be viewed as random error.

4. For performance above chance, the curve will lie above the diagonal.

5. While many textbook ROC curves are symmetrical about the negative

diagonal from (0,1) to (1,0), it is not necessary that this be so.

6. If a second ROC curve were generated by altering the stimulus, or by

using a different observer, a higher hit rate at a given false alarm

rate would mean better performance at that false alarm rate. More

generally, when a signal is highly detectable to a subject, the ROC curve will be high for all false alarm rates, meaning that it rises

steeply from (0,0), and then bends over rather sharply near (0,1). A

barely detectable stimulus will give a curve near the diagonal. This

is illustrated by the family of ROC curves in the lower graph of

figure 1.

7. ROC curves can be used to compare different stimuli for detectability

or different observers ("receivers") for performance. We now see,

however, that it is not meaningful to compare two observers on the

basis of hit rate alone. To say that Subject A performed better than

Subject B because A caught 80% of the counterfeits presented while B

only caught 30%, would be completely false. By a change of criterion,

B could raise his/her hit rate to 90% or 99%. What we need to know

is the relationship of hit rate to false alarm rate for each observer,

22
FALSE ALARM RATE

Figure la. An ROC curve from an hypothetical experiment in which

a person has been asked to detect a brief tone. The stimulus and

the person are the same for all data points. Only the observer's

criterion changes from point to point. An experimenter can

affect criterion through instructions.

Figure lb. A family of ROC curves corresponding to stimuli of

differing detectability (after Jeffress, 1964). These curves

were derived from a theoretical model of detection of sounds.

They show how the ROC curve becomes higher and more angular as

the signal is made more detectable. Analogous data for other

types of detection experiments might have given curves which

would differ in exact shape.

Figure 1. Hypothetical ROC curves showing effects of shifting

criterion and stimulus detectability.
and this is what the ROC gives us.

8. For practical work, it would be desirable to reduce an ROC to a single

number, a measure of overall detectability or performance. One such

measure is simply the area under the curve. Any such number derived

from the entire ROC can be called a criterion-free measure of

performance.

24
3. Results

3.1 Overview

Results from the pilot study include: the participants’ performance in

identifying counterfeit and genuine bills; performance on individual bills;

comments about individual bills; overall comments about the decision process

and features noticed; and spectroradiometric measurments of counterfeit and

genuine bills. Data for each type of result will be discussed in turn.

3.1.1 Detectability of Counterfeits

The first set of data to be discussed is the frequency of detecting counterfeit

bills in the stack of 102 bills. Table 1 presents data on decision frequencies

for each counterfeit denomination, as well as for the whole set. In this

table, C refers to identification of the bill as counterfeit, and R refers to

identification of the bill as real (genuine). Thus, C/ C means counterfeit

identified as counterfeit, C/R means counterfeit identified as real, R/ C means

real identified as counterfeit, and R/R means real identified as real.

Table 1 presents the raw data for each observer for the task of detecting

counterfeit bills in a series of mixed counterfeit and genuine bills. From

these data, it is readily possible to compute a single false alarm rate and a single hit rate for each person. The data are plotted in an ROC format in

figure 2. The number by each point identifies a specific observer's performance.

While these are not appropriate data for plotting an ROC curve in the ordinary

sense, using this format provides useful information about overall detectability

of counterfeits and the variability between observers.

If all observers were equally proficient at detecting counterfeits, but operating

at different levels of an internal criterion, the data would indeed follow a curve with the typical appearance of a Receiver Operating Characteristic.

This was not the case.

Nevertheless, we can observe that:

1. Observers 3 and 4 operated at the same false alarm rate, as did

16 and 18; 9, 11, and 20; 2 and 7; 1, 14 and 17. In these cases,

it is clear that observers did not perform equally well; observer 1 did better than observer 17, for example.

2. Observer 4 performed better than observers 5, 11, 16, 18, and 19,

since observer 4’s ROC curve must proceed upward monotonically from

the known point

3. A rough surmise can be made of the ROC curve for a typical observer

in the group, the particular stack of counterfeit and genuine bills,

the specified lighting conditions, and the overall level of training.

This estimated curve, fit by eye, is indicated on figure 2.

25
Figure 2.

presented

FALSE ALARM RATE

Detectability of counterfeit money for 21 observers

in ROC format.

26
Table 1- Observer Decisions about Counterfeit and Real Bills

Total

Observer Sex C/C C/R R/C R/R Correct

1 M 22 0 29 51 73

2 M 20 2 23 57 77

3 M 13 9 6 74 87

4 M 18 4 6 74 92

5 M 16 6 25 55 71

6 M 21 1 19 61 82

7 M 22 0 23 57 79

8 M 22 0 62 18 40

9 M 19 3 21 59 78

10 M 9 13 0 80 89

11 M 16 6 21 59 75

12 M 20 2 22 58 78

13 M 21 1 7 73 94

14 F 21 1 29 51 72

15 F 22 0 38 42 64

16 F 16 6 14 66 82

17 F 18 4 29 51 69

18 F 11 11 14 66 77

19 F 15 7 16 64 79

20 F 18 4 21 59 77

21 F 7 15 3 77 84

Mean - Males 18.4 3.6 20.3 59.7 78.1

Mean - Females 16.0 6.0 20.5 59.5 75.5

Overall Mean 17.5 4.5 20.4 59.6 77.1

Overall Std. Dev. 4.42 4.42 13.6 13.6 11.3

27
In addition to providing raw data for the ROC analysis, Table 1 provides

specific information on the performance of each individual. As the ROC analysis

indicated, a number of people had high false alarm rates, in which they identified many genuine bills as counterfeit - and provided many comments about

(real) printing flaws in the process. Others tended to accept all bills as geniune, while still others tended to be quite accurate - rejecting counterfeits and accepting genuinue bills. Both criterion and ability differences

probably account for individual variability.

To turn to specific performance, examination of table 1 indicates that four

people identified all 22 counterfeits as such, while five more identified 20 or 21 accurately. For genuine bills, one person identified all 82 bills correctly, while four others identified 73-77 bills (89-94 percent) accurately.

At the other end of the continuum, one person identified only 7 counterfeits

correctly, while another person identified only 18 genuine bills correctly.

Thus, a wide range of ability and/or criterion differences were represented.

It should be noted that chance performance alone would result in accurate

identification of only 11 counterfeits and 41 genuine bills. No observer’s

performance was at this level. Clearly, however, the task of identifying

counterfeit bills correctly is not so easy that everyone does it accurately.

The data were analyzed by sex of participant to determine if any differences

existed. The eight females made more errors than the males, particularly

with the counterfeits (mean of 16.0 vs 18.4 for C/C) . This difference may

have occurred because the females were primarily housewives, students, and

secretaries, while the males were professionals and technicians, and possibly

more familiar with larger denomination bills. The females tended to make

slightly more errors with the $ 100’s, as well. In fact, many of the observers

expressed unfamiliarity with the larger denominations—which comprised much of

the set of bills.

Table 1 can also be examined to obtain an idea of overall detectability of

counterfeit bills. Thus, for C/C (correct identification of a counterfeit),

the mean number correct out of 22 was 17.5 (with a standard deviation of 4.42),

while for R/R decisions, the mean number correct was 59.6 (out of a total of

82). To compare the results for counterfeit and genuine bills, the data can

be expressed in terms of percentage of the total number of each type of bill.

Using this approach, it can be seen that the percentage of correct responses

was similar for the two types, although it was slightly higher (78.4 percent)

for counterfeit bills than for genuine bills (74.5 percent).

Thus, participants were slightly more accurate in identifying counterfeits as such, although even so, they made errors about 20 percent of the time.

3.1.2 Accuracy of Identifying Individual Bills

Table 2 presents data on the frequency of making errors for each counterfeit

bill. The mean number of errors for all participants in detecting counterfeits

accurately was 4.32, with a standard deviation of 2.9. No errors were made

for one bill, 321 7C, while only one error was made for two other bills, 1381

and 4051D. Two bills proved particularly difficult - 3691H with 12 errors or

28
Table 2 - Frequency of Errors Made in Identifying

Counterfeit Bills

Serial Number

Errors Mean Errors

Denomination Per Bill Per Denomination

Total Errors Per

Denomination

0324E $10 4 3.33 10

0436D 10 3

3752F 10 3

0759* $20 5 2.67 16

3271C 20 0

4051D 20 1

6786A 20 2

9111B 20 2

9197C 20 6

0395D $50 6 6.00 36

1381A 50 1

2236D 50 2

3691H 50 12

8194A 50 5

9428A 50 10

1292A $100 5 4.71 33

3807A 100 4

4275B 100 7

4967A 100 5

6554A 100 5

7868A 100 5

9235A 100 2

Overall Mean Errors = 4.32

Overall Total Errors = 95

29
incorrect identifications, and 9428A with 10 errors. Both these $50 bills were incorrectly identified as genuine by most of the observers.

Table 3 presents similar data for the genuine bills categorized by denomination

and by wear category. The table presents the number of errors, or the number

of times a genuine bill was termed counterfeit. The overall mean number of errors for the 80 genuine bills was 5.6, with a standard deviation of 2.75 and

a range of 1 to 13.

The data are further discussed in terms of wear category and denomination.

In terms of denomination, $ 100's were most likely to be termed counterfeit and

$10's least likely, although there was a large effect of wear category. As

table 3 indicates for $10' s, the overall mean frequency of "counterfeits"

detected was 4.6, with "good” $10* s somewhat more likely to be termed "counterfeit". Table 3 indicates further that the mean frequency of terming a $20 as counterfeit was higher - 6.2. "Very bad" $20' s were most likely to be seen as counterfeit, with a mean frequency of 9.33. "Bad" 20' s on the other hand were

much less likely to be termed counterfeit, with a mean of 3.57. The mean

frequency of detecting counterfeits for $50's was 5.0, and for $100's was

6.55. For both denominations, the more worn the bill, the more frequently it was termed counterfeit. For both 50* s and 100's as well, the "very bad" wear

category was most likely to be termed counterfeit, with mean frequencies of

7.33 and 9.17, respectively.

Although counterfeit bills were not classified by wear category, effects

related to denomination were observed. Table 2 indicates that counterfeit

10' s and 20' s were slightly more likely to be identified correctly as counterfeit than 50' s or 100's. The number of errors tended to increase with denomination for counterfeits with mean errors of 3.34 for 10 f s; 3.2 for 20* s; 5.14

for 50' s; and 4.71 for 100’s. Considering both counterfeit and genuine bills, error rates were most similar for $50' s, and most different for $20' s.

3.2 Features of Bills Noticed During the Pilot Study

3.2.1 Comments Made During the Examination

Examination of the comments that observers made while examining each bill can provide some clues about the features that people noticed about the different

bills. Table 2 of the Appendix presents a listing of all comments made for

counterfeits first and the genuine bills second. Review of this table indicates

that the total number of comments was typically much larger for counterfeits

than for real bills. In addition, many of the comments for genuine bills

simply indicated that they were "OK".

Because of the volume of comments, comments were categorized so that some conclusions could be drawn about the features typically noticed. The following

arbitrary categories were developed from the comments given by participants

30
Table 3 - Frequency of Errors Made in Identifying Genuine Bills

Serial Number Denomination Wear Category Errors

0768A

1278B

2679A

2885 A

3494B

7333B

8361A

0100A

4296 E

5178B

5802A

6228C

7632E

9139B

1372A

1695A

4317C

6854C

7949B

8686B

10 Good 6

7

7

6

6

1

7

10 Bad 4

5

5

4

3

1

5

10 Very Bad 9

3

2

3

4

4

Overall Mean for $10' s =4.6

1741D $20

1941D

1942D

3267C

6101B

7968D

8389F

0267A $20

0716B

1227A

5654A

6092A

6919B

7293*

2998B $20

3297A

4869*

6295E

7234E

8638C

Total Errors = 92 ( 21

Good 8

5

7

6

4

5

8

Bad 4

5

2

4

1

5

4

Very Bad 6

9

12

11

8

10

Mean

5.71

3.86

4.17

9%)

6.14

3.57

9.33

Overall Mean for $20' s =6.2 Total Errors = 124 (29.5%)
Table 3 Continued

Serial Number Denomination Wear Category Errors

1855A

6381B

6592B

7144B

7741B

7921B

9882B

4967A

5311A

7104B

8081A

8350A

8731A

9052A

1139B

2507A

7701A

8776A

9265A

9695A

50 Good 1

1

2

4

2

2

3

50 Bad 2

12

6

6

5

4

6

50 Very Bad 8

11

6

10

3

6

Overall Mean for $50' s =5.0

0934A 100

2119A

2136B

2860A

4108B

5318B

7405A

0046A 100

0107A

2792A

2844A

3157A

5372A

5925A

1235A 100

3251A

4723 A

7183A

9159A

9602A

Overall Mean for $100's = 6.55

Total Errors = 100 (23.87)

Good 4

3

6

6

6

6

5

Bad 7

5

5

5

7

7

4

Very Bad 8

8

8

10

8

13

Total Errors = 131 (31.27.)

Mean

2.14

5.86

7.33

5.14

5.71

9.17

32
GENERAL

Paper Wrong - PW

Paper Feels Wrong - FW

Bill Looks Funny - LF

Creased/Folded Wrong - CR

Unfamiliar With Design - UD

Information, Design Wrong - IW

COLOR

Too Yellow (usually paper) - TY

Green Wrong - GW

Color Wrong (either ink or paper) - CW

Black Wrong (usually ink) - BW

CONTRAST

Too Dark (Black Too Dark; White Too White) - TD

Too Light (Too Grey) - TL

DETAIL

Lacks Detail, Sharpness, Looks Like a Photocopy - LD

Printing Defect, Ink Smeared or Spotted - D

Problem With Portrait - PP

FADING

Faded Wrong, Dirty - FD

Wear Inconsistent With Age - WA

COUNTERFEIT CHARACTERISTICS

Blunt Points on Seal - BPS

No Threads - NT

Borders Trimmed Wrong - IB

Because many people made more than one comment about some bills , the total

number of comments is greater than the total number of participants. In addition, it was difficult to categorize some comments. Thus, "Looks like a xerox”

was treated as lacking detail (LD) , while "Looks washed out" was treated as lacking contrast or too light (TL). Comments relating to printing press quality, such as "looks blotchy" or "stray ink" were treated as a printing press

defect problem (D)but it was sometimes difficult to separate these type of

comments from those relating to lack of detail. Thus, the categorization must

be treated as an approximation, and the comments, given in Appendix A, read in

detail, to learn more fully what each person reported.

The comments in each category were totaled to provide an overall indication of

the types of problems that were noticed about both counterfeit and genuine

bills. Table 4 gives the total number of each type of comment for both

counterfeit and genuine bills, as well as the frequency for each comment for

each bill type.

33
The greatest number of comments about counterfeit bills were made for the

following categories: Feels wrong (95); Color wrong (74); Portrait Problems

seemed to refer either to appearance or feel, but not enough information was recorded to distinguish these categories. When specific information was given,

it was categorized as either looks wrong (LF) or feels wrong (FW). Other

comments that were noted frequently included too much or too little contrast

(TD and TL, 41 and 33, respectively).

Examination of table 4 indicates large differences in the frequency with which

particular comments were made between counterfeit and genuine bills. For

counterfeit bills, comments about problems with the portrait, color, contrast,

feel, and overall detail were made at least 4 times as much as for genuine

bills. Comments about the paper being wrong, the bill looking funny, and wear being inconsistent with age also occurred with far greater frequency for the

counterfeits. In contrast, the most frequently occurring comment for genuine

bills was that the bill was "OK". The second most frequent was that it "felt

wrong". In fact, comments about feel were common for both types of bills.

People appeared to have strong notions about how real bills ought to feel.

These notions were not always accurate, however, and sometimes seemed to confuse,

rather than help participants. Nevertheless, comments about "feels wrong"

occurred 4 times more frequently for counterfeit bills.

For genuine bills comments about "feels wrong" also occurred frequently. Only

one category (other than "OK") received more comments for genuine bills. This

category "irregular borders," referred to the amount of white under left on the edges of the bill. (Trim errors of this type were rare for counterfeit

bills.) Table 4, thus, indicates numerous defects observed for counterfeit

bills. These defects, relating primarily to the portrait, color, feel, and

overall engraving quality appear to be the cues used by participants to

distinguish counterfeit bills from genuine bills.

Table 5 presents the comment data categorized for each serial number. The

most important thing to note is that fewer comments were typically made for

genuine bills. For these bills, the range was 5 to 23, compared with 20 to 44

for counterfeits.

For counterfeit bills, bills receiving 38 or more comments included 0759*,

2236D, 1381A, 3271C, and 6786A. Bills receiving 21 or fewer comments included

369 1H, 8194A, and 9428A. The counterfeit bills for which large numbers of

comments were made generally received fewer identification errors; in other

words, they were correctly identified as counterfeit.

Examination of table 5 indicates that different bills received different types

of comments. Thus, 6 or more comments about contrast were made for 2236D (too

dark), 4967A (too light), 6786A (too dark), while 4051D, 0759*, and 8194A were

considered to feel wrong by 6 or more people. Frequent comments about wrong

color were made for 1381A, 3271C, 4967A, and 4051D. Portrait problems were

were particularly pronounced for 0324E and 327 1C. Lack of detail was also a problem with 1381A, 2236D, 4051D, and 6554A.

34
Table 4. Total Number of Comments in Each Category for Each Bill Type

FORGED

PORTRAIT PROBLEM 92

FADED, HORN 17

HEAR WRONG FOR AGE 14

BLUNT POINTS ON SEAL 9

NO THREADS 24

IRREGULAR BORDERS 6

OK 3 PAPER WRONG 47

FEELS WRONG 95

LOOKS FUNNY 19

CREASES WRONG 9

UNFAMILIAR WITH DESIGN 6

INFORMATION WRONG 1b

TOO YELLOW 23

GREEN WRONG 22

COLOR HRONG 74

BLACKS WRONG 11

CONTRAST TOO DARK 41

CONTRAST TOO LIGHT 33

LACK OF DETAIL 84

PRINTING DEFECT 19

TOTAL RESPONSES 671

TOTAL BILLS 22

FREQ/BILL GENUINE FREQ/BILL

4. 1 3 36 1.11

0. 77 46 0. 58

0. 64 1 0 0. 1 2

0. 41 25 0. 31

1. 09 60 0. 75

0. 27 39 0. 49

0. 36 1 32 1 . 65

2. 1 4 62 0. 78

4. 32 1 1 9 1. 49

0. 86 34 0. 42

0. 41 27 0. 34

0. 27 17 0. 21

0. 73 41 0. 51

1 . 05 1 4 0. 1 8

1 . 00 1 8 0. 22

3. 36 47 0. 59

0. 50 15 0. 1 9

1 . 86 30 0. 38

1. 50 23 0. 29

ro CO CM 38 0. 48

0. 86 63 0. 79

924

80

35
Table

5.

Number

of

Comments

in

Each

Category

for

Each

Bill

<cpXIO'

3-

PO ooocMmmoocM OCMorOOCI'r-O to to cn

CQLO

PC\J or

<oaaoooaoio<-omoo<-o<-o<-ioo o p01

a araoooaoop-r-ooocM<-ooon<-ptoo

or

p-cn

<33 p~o

00cn

o'ooc-ojajoonoooooor-mooajojo o =t cn

t-u CMop-00

CM

OO oomo«-oo<-oocMr-oo=rc- cm

m

<D

S3 mOO^-r-OCMOCMr-OOr-O

a

O' cn xi

-3 cn j m cm o CM

CM *

CQ

O

r—

!- P- M CM

cd cn

CI4 z

cda

E- XI Z cn

CO CM O CM 0

OCMCMO*-CMOorCMO<-Oc-CMr-OOPn<-C'-0 O'

O

m

cnoo<-cnoacMX>o<-ocMOcncnora'OM30 cn cm or

<33

00cn cMOaar-aaonor-*-ocMx>cna'r-mox>o cr

or

<33 CMO'

CM

CM

O cMOt-cMora<-o o or

a cm <- to O' to

CM *

O'to

p-o

lOCnCMr-CMOaOCrCnr-Or-Or-CMt-orCMCM o to

or

a

MOcn

oro

CfimCMOCMWOorCMrrO xo o *- o m <- or cn cn

a

to

O'cna

p- o a Or-CMc-CMOO*-OOCM<-OorCMO MO X)

CM

Cd orcnoooooorcMOr-oocMOxjo

CMcno o c— or

cn z0

l-t as cn Cd Cd Cd h- C3 CO CO Q O z z

<0 OS z z CO Cd z Cd z 0 <33 M E- cn -3 z 0 a E- z Q J X] O Cd

CQ 0 z 0 z z M Cd cn O Cl4 cn 0 z z O O O <33 Cl4 z cn a z s— CQ a CO >• 0 z a CJ z O O Cd 0 z

04 as

a z cn z Z z z z 0 z z z 0 H- E— Cd

a a, 0 0 z n Q Z 0 O z z <3 l-l 0 0 0 z Q cn z H z 0 0 <3 03 z z z M E- -3 z z z H E— CO Cd z M z a. Cd -3 z z z cn -3 <13 -3 z z cn cn Cd z z Cd

<33 as Z Z Cd

M z Cd cn <33 <33O l-l a; Q E- Z O z cn cn cn z z >- z z z Z z h- -3 -3

E- Cd z Z E- Cd Cd -3 z as <33 0 Cd 0 0 E- E- z z <33 <33 as a <33 3 Z z u 0 Cd Z CI4 O Cd -3 <33 Z Z CO M E- E—

0 as u J O z Z as w 0 z z z O Z O -3 O O <33 z O O

04 Cb z Z Z l-l

O Z z j 0 z l-l Ea CO CQ

O CO -3 z f- E36
COUNTERFEIT

REAL

OQ O O O 5- O OJ o «— OOOOOr— OOOOCM

sO o' n

C'- o

3

oXI

CMo

CMOOOOOCMr-*-OOOOOOOt— OOOCM O' -3

"

3

o

o

o o o o o a<-o*-a<-Or-oor-o co in

c

3

a

o

OOOCMOCMOOOOOOOOr-OOOCMO 00 sr

a

3

X

=ra

o

o o a o o 3-Or-ocnoooooo c^

*300

CM3" O*

CMCM«- 0 t- 00 CMCnt- 0000 T-CM 0 r- 03'CM CM O

CM r3

n

no

CMO'

n oo OO 3 CMCMOOOOOr-OO>0 nr- CM CM m

o

rO'

ca

cm o CM n O 5- rmOOOOOaCMC'-OOOan

m a 3-

oo a n

CM

3

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CM

O'3

=t

O' 3

- 0 CMa*- 00 CMa' 0 <- 0 a 0 r- 00 cM 0 mt- x> n

CM

oo

<300

XJ03C00 O O t- 3- O 03r-OO<-CM00r-COCMr- o n

00

3

X)03

DM3

00OOOOOO3‘00<-OOr-3’t-3-OX>t-CM*0 X) CM 00

-33" n

n

XI

x>cMaaooacMoocMaoa<-03-oocMi>o cr> n

CM

T3

a>3

3

3

OO

n

0) r—

(

XI3H

z

C3 X t-i 3 CO

cd Cd Cd (- a CO CO Q O Z 03 CO 3 a: Z cc u (X

Cd Z Cd D3 o 3 HH CO O X OS o a f- z X X -3 o u GC

CQ o as u hH z H Cd CQ GC o Cd CO O z DC o o. o 3 Cl4 z Cd z z H 03 a a >- o z 3J CJ z o o H Cd O

04 cc o Z CO z z z z CC o z Z z o (- H Cd Q Q» -J o z 1—

Q CC o o z z l-l o o o z Q CO H z o o 3 3 cc ac s hH f- X z z ac (— O Cd h- M cc 04 Cd X z Z C«4 CO -J 3 X z z CO CO Z Z GC O

3 z cc S3 Cd M X Cd CO 3 3 o H hCC a h- S3 a cc CO CO CO X z >- z z z z H •J H Cd CC Z f- Cd Cd J M 3 <C o Cd o o t- (- Z

CC Q 3 S3 CC au Cd o Cd C*4 Cl4 o Cd -3 3 z z o H

o 3 Cd -9 O CC 3 Cd o CC as z o Z o O o 3 CC O

04 Cl4 Z CQ z M O 04 Cd X o CD H u o CD o u -1 a, H

37
Table

5

-

(Continued)

OQM3mC\J O O <— O O O t— r— k— O O O O 4— t— O O O t- O O' '-O

CM

<«1 O' ooooooojr-oooojoar-ooocMoo oo m

CMa

CMsr

O' ooaooo<r-o^-r-ooooor-Or-Or-m o' e'-

er

O' OOOOO^Oc— OOOOr-Or— «— Or-OCMCM O UO

<cLO

00

00 OOOOOO^-OOOOCMOOOOOOOOO M3

sr

c- OOOOO3-OOOOOOOOr-T-3-«-00C\i A CO

<c

Lpl O'

M3 ooor-oonor-o«-oooooooooo C'- cn

«0

CM

e'- en m<r-*-<-r-oom.=ro*-ac-o<-oaaa<-o co o'

03COcCM 0000CMCM«-t-000000*-*-r-0<-CM CO C-

<0

ITl cn

CM

CMCMOOOO<“CMC'-Or— Or-OOOOOCM O 00

CM

«sj c-- CM

CM OOOOOCMO^-t-OOOOOOOOOOO A CM

03O'

cn 00t-CM<-CMr-=Tc-00c-0a<-a00r-0 M3 CO

<D=tcn

O'o

OOOOOCMr-t— OOCMOOOOOOOOO C'- sr

<5 COAA

o

cnooooaa-ocMooacMOOt-acooo CM A

'sc o

A A

cn 2 w 2 A

u cn cn Q a SC 2 cn 2 •a) CC 2 2 o 2

m sc 2 SC O *si A A cn O

A CC o Q A 2 Q A A O 2 2

m o CC CJ M 2 A 2 cn 2

o 2 cn o 20 SC a O O 03 2 2 2

2 2 A 03 a O >- o 2 CJ C3 2 O o A 2 O

04 cc U 2 cn 20 20 20 CC CC O 2 2 2 O A A 2 a 2 A

o a A Q CC o O 2 SC <S A o O O 2 Q cn <J3 A sc o O <q <C cc CC S3 A A A 2 2 2 A A C3 2 A

A CC Cl. 2 A as as 2 cn A *aj A 2 2 cn cn 2 2 2 O

•03 „ sc CC S3 2 M 2 Cd cn «C O A A

CC Q A SC a cc cn cn cn s 2 >- 2 2 SC 2 2 A A

A 2 cc 2 A 2 Ci3 A SC <3 O Cd O o A A SC 2 «J3 CC Q «n S3 CC Ot 2 o 2 2 Cn O 2 A •< 2 2 o A A

O <0 2 A O CC SC a} 2 o CC 2 2 o 2 O A O O oj 2 O 2 2 sc 03 SC A o CU 2 A o S A A C3 O 2 O o A 2 A

38
2507A

2679A

2792A

2844A

28bOA

2885A

2998B

3157A

3251 A

3267C

3297A

3494B

4108B

4296E mr-Ot-CJr-c-r-OOr-t-r-OOt-OOOt-O LT> CTl

oooor-mcoomooo^-oooot-o^r- m -o

ooa<-oomar-<Mooaaooaojooc\i «- x

C\J0Jr-Oc-Or-Or-OOOOmr-J3OOOOO Q3 CT

oooooom,-<-aooaac\jooc\jOr-.=r

onr-Or-fnoooLnOt-oojaoooor-oo 2 oo

OOc-C\IOOOC\JOOOOOO«“*“ «— 2

c— ^ 00c-0<-C\Jr-000t-a0r-r-0000 P"> nD

<- O O r- c- 0 OOt-5-OOOOOOOJOOO vO

moooe-cvjojojo^-or-oooooof-o £)

OOr-r-OOCMmOJOt-OOOOOOOOO LO

T3

aj

maor-oooono*-ooooo«-aoo

ojoOr-r-ooc\JonjajoOt-o»-ooT-ooo

ooa'oooooooc-aor-or-ooooooo

2

«e Cd Cd

2

03

COCd

LP

£ 1 os CO co Q 03 2 2

•H 1 2 «: 2 2 2 03

4-1 1 Cd 2 Cd 2 O 4 2 CO £ 1 X 2 O a 2 2 a 2 2 O Cd O 1 03 O 2 03 2 2 2 Ci] CO U 1 O b CO o 2 2 03 o O aq Cl4 2

v— 1 2 2 2 2 0

3

03 >* o 2 a 03 2 o o 2 u o

! a. co 03 2 CO 2 2 2 2 2 O 2 2 2 o 2 2 Cd a 2

1

I o 2 2 Q 2 O O 2 2 <s 2 o O o 2 Q CO

1 2 2 O O <1 •a: 2 2 2 2 2 2 2 2 2 2 o Cd m 1 2 2 2 Cd 2 2 2 2 CO -J «a 2 2 2 CO CO Cl, z 2

1 as - 2 2 2 Cd 2 z 2 CO as O V-H <u i 2 a 2 2 o 2 CO CO CO Z 2 2 2 2 2 2 2 h 2

rH 1 2 w 2 2 2 Cd Cd 2 2 •as <c o 2 O o 2 2 2 Z -< x> 1 2 Q <1 2 2 2 cd O 2 2 2 o 2 2 2 o k—

«

2

cO 1 o -a? Cd 2 O 2 2 a: Cd O 2 2 2 o 2 O 2 O O a) £X O H i a, Cl4 2 2 2 2 O 2 2 X O 2 2 2 03 o ffl O O 2 a. 2

39

TOTAL

ERRORS
Table

5

-

(Continued)

o

00

CM

CMmo ooooo=roooooooooooooc\j

00o

o

aioooomt-oor-oooo«-c\jocvjo«-sf i> 3-

c

CMO'o

MO ooo-r-ocMoaoaoooooooao LO

<8n

CMO'LO

r-OOOr-OCMc— O 00 O O O CM O O O 3- 3-

<8CMO

00in

CM O O O CM O O O O O O s— 3"

<83"m

MOn

cMO<r-oaocM<-<-Oc-oaooor-ooao cr 3-

<8CM0-

00

L0l

O O O CM O CM O O O O O O a o O P000000

in

00

in

OOr-OOOOr-CM o o o o o

OOT-r-OOOCMOOOOOO

CM O

0 0 83-00

3- MO

O CM

CM t—

00COc-m

r- O O O r- O O00OOOOOOOOc-O<-<^ O' in

O'MO

CO

3-

CM-r-OCMOOOOOOCMOCMMOOCMOOOOO CM

<800

CMc3-

CMCMOOCMOOCMnOOCMOOOCM O o o CT CO

o

l>00

3-

CM O O O O 00 O CM O O O O O O O O O O O CM

X

u

X X

<3 CO X X X (-* O CO CO Q a X X CO X <3 X X X a X

x X X X o <8 EH E— CO o

-3 as o Q E- X Q J X O X X

CO O X o M X M X co X

O X co o X X a o o <8 X X X

as so E— X o O >« o X o a X o o E- X o

& as o X CO X X X X X o X X X o E— E- X Q X X

o X l-l Q X o O X X <8 l-l o o o X Q co «8 E- sc o o <8 <8 X X X EH E- -J X X X E- E- a X E- M as a, X X X X X CO X <8 X X X CO C0 X X X O

•8 „ X X X Cd l-l X X CO 8 «8 O l-l Eas Q E- X a X CO CO CO X X >- X X S8 X X E- X

E- X sc X f—x X X *8 *8 «8 o X o o E- E- X X <8

as Q aj X X X Cd O X X X o X X «8 X X o X E- o <8 X X o X <8 Cd O X X X o X o X O O <8 X O

x X X X X w o X X X o X EH E- u o X o o X X E40
Table

5

-

(Continued)

o

C'- C"

CjJ C\J oo

•S3 p03ino

•Zp-m

m

m

oo

p-

<

oo

O'

CMP-a

=roo

f\J a

<s00

CO

CQ

cr

CQS’o

CQO'

O'a

in

CO

•S3

CQ

CMO'in

S3

ooooooonjcunir-oooooo^or-oo cm S3

oooo=ro<-oao<-oaooooor- o'

OOOr-c-OOOCMCMOOOOOOr-OOr-CM O LO

OOOOOO00OOnJOOOOOOOr-OOO a

Ot-OOOOr-Oxr-r-OCMOr-t-r-OOOcooooot-oojoooooj^-moooc-o in oo

o o OOCOOOOOOxOCM oo o

OOOOOt— OOJOOOr-Ot— t-Or-Or-<— O Z

acMoacMaoazxr-aaoaooooocM cm =r

aoaocM*-cMoaxoaooaooo<-ocM cr in

r-OT-OOC\JOOr-t-OOOOC\iOOOOO O 00

oooooosrr-aooor-or-or-oooc oo c\j

CQ

r— CO00

•S3 oooooooooor-or-oor-oaoooo a

a

in

O'

CM

M3

CMCMOr-CMOt-aZ Ot-CMOCMOr-Ot-O

z

a

a X

«u CO a a a a

u co co CJ o X X

z <c X z X o

a z a X o 03 X f-* CO a cc o Q a X Q a a o a

CQ o X UJ X X X Cd co O a CO o z X o O o OJ Lu z

CC as H m a o a o z a O z o o a C

o

cu x o z CO z z z X X o X z z o a a a a a

o z X Q X o o z X 03 X o O o X Q CO a X o O <U <3 X X s X a a X X X a a u a X cc Oi a a X X a CO a 03 a X X co CO a z X

OJ „ X X B a X z a CO < OJ o H

ce Q a X U X CO CO co z X >* z X X X X a

H a X z a a a a X <3 OJ o a o o a a JZ Z <s X Q OJ CD X X a O a a a o a a OJ z z O >—

a

o OJ a a o X X oj a o X z z o cc o a O o CC o

a. a X ca z M o X a a o X X a O o a o o a a, a

41

TOTAL

ERRORS
<aj vO0-

F-CO

C\JOO^mOOL0r-OOO0JOOCMOOOr-O

on

c-oo

35on

co

COo

00

o o o on OOOr-t-OOOOOOOO

03

-JO CO

3>00

CM CM O O OCM<-CMOc-OOOOOOOt-Oa

o

COon

3)00

CM O on on or o o o o o =r o cm CM O nOCM

Cl4 O'CO

on

00

onoOr-oocMOonooooOr-oocM^-oon 3>

o o O O on OOr-OOOOCMOOr- CM

O

cn

on

co

OCMOt-r-OT-t-OnOOOOOOOOOOr-O in

o o o o N m o oooooooo o o

Q

co

3>O'

l> cMOOOooonooooo OOOr-OOOnn in

03O'

•aO'

C'-

O O CM O O CM oooooooooooo

03

rCMO'c- OOOOOCMOO OCMOOOOOOOOO CM

03

*

=r

c-cO O O O O O CM CM O O O O O O O O CM

T3

0)3a

•HU

3

O

C_)

I m

QJ

i—

32

cd H

-3

03

a

u

co

DO DO a E— U 03 co Q u a a co

2E 33 a a a C3 a

DO a Ci3 a o <33 M E- co o

_J a o Q H a Q a a O a a

03 o a a M a M a CO a

O a co o a a u o o 33 a a a

CC a e- a CJ u >- o a a u a o o E- a o

Cu a u a co a a a a o a a a o h E- a a a a

o a M Q a O o a a «3 M o o o a Q CO 03 E- a o o 33 «3 cc a a M E— a a a a !—

E-1 a a H

l-H a a Cd a 3= a a co a <33 a a a CO CO a a a O

«aj a a s a M a a CO <r) <3 o M H

OS Q E~ a C3 cX CO co CO a a a a a a a E— a

U3 a a e- a Cd a a •33 <q o a o o e- E-1 a a 03 CC Q as a a 04 a o a a a o a a «3 a a o M E- O «J Cd a o a a <S a o a a a o a o a o o «3 a O

cu Cu a a a i—

o 04 a a o a M E- u o m o o a a (—

42
9052A

9139B

9159A

9265A

9602A

9695A

9882B OOOc-r-O^-t-CVJOOr-OOOOOc-OOO <- 00

cM000c-0mcvj00CM0000t-t-0r-00 on xO

moojooo?-«-rjooor-oot-oor-o-o co on

cvjoooo^-r-r-Or-^-oooor-oooo o' on

o =r C\J o o o o o o o o o o CO

o o o o o

O O CJ o o on o cm o <- o o o o o o o

1 z

X 1 u

T3 1 l-H OJ 1 «3 co 3 1 Cd Cd Cx3 E- 3 1 U CO CO Q CJ B S •H 1 X <3 CC z CC u U 1 u z CO B o l—l h CO 3 1 J CC o Q E— ac Q _3 -3 O Cd O 1 CQ o CC a l-H B l-H W CO

'O—

1 O CI4 CO o z B CJ O o 4 Du z

1 CC z E- m <3 3J >- o z o CJ z o o 1— CjJ o

l a. CC o z CO z z z ac ac o B z z o t— Cd Q a.

1

i o z M Q CC o o z B 4 l-l o o o ac Q CO m

i E- ac o o «3 •>J3 ac ac z t—

f— -3 ac CC B h- E-" O Cd

1 M CC 04 Cd -1 B B Ct4 CO -3 •413 J B B CO CO 'JU Z CC

0)

1 <3 ac cc z Cd l-H X Cd CO «3 <c O UH

i ac Q H B a CC CO CO co XL ac >- Z CC B CC ac H _3 rH 1 E- Cd CC Z E- u u -3 B «J3 <c O Cx3 o O E- E- B Z

J3 1 CC Q «3 z a a. Cd o Ci3 CX4 Cl4 o Cd -3 z z O HH H 3 1 o < Cd -3 o oc B «3 Ci3 o cc z z o ac o -3 o O ««3 ac O H 1 04 Cl4 ac CO z w O a. C*4 J o z h-t E- a o m o o -3 cu 1—

TOTAL

ERRORS
Two counterfeits (3691H and 9428A) had many errors, and relatively few comments.

Yet, the 20-21 comments they received, while a low number for counterfeits,

was a high number for genuine bills. This suggests that people noticed something about these 2 bills that they did not notice about most genuine bills.

For genuine bills, the number of comments varied from 5 to 26. Bills 1227A,

1885A, 6092A, 6381B, 7333B, and 7921B received only 5 or 6 comments, while

bills 1235A, 4869*, 531 1A, 8638C, and 6295E received 20 to 26. Large numbers

of comments were typically made for the bills which received many errors (8-12

errors) unlike the counterfeit bills. Bills receiving few comments, on the

other hand, had few errors (1 or 2).

For genuine bills, 2 bills (5311 A and 8081 A) received 6 or more comments about

irregular borders. Other categories with 6 or more comments included:

wrong color (2235A), faded (2507A), color wrong (3297A), too yellow (4869*),

and printing defect (9602A). Unlike counterfeit bills, comments about problems

with genuine bills did not cluster into categories. Furthermore, relatively

few comments were made about portrait problems, poor contrast, or lack of

detail for genuine bills, even though many such comments were were made for

counterfeit bills.

At the end of the session, participants indicated the features that generally

seemed to be most important in recognizing counterfeit bills. Table 3 of

the appendix lists the features that each person considered to be most important for all bills. Each person also indicated if the noticeability of these

features changed during the course of the study. Review of the comments in

Table 3 of the appendix indicates that about 16 people thought that feel was

an important cue in detecting counterfeits. Thirteen people indicated that

color of paper, portrait quality, and sharpness of lines and detail were

critical, while nine commented on shading, fine gradations, and contrast as important. Eight believed that problems of wear relative to age or intentional

aging served as good cues. Only five people mentioned threads, with the

majority of these comments relating to the difficulty of finding them in the

set of bills used. Six people mentioned problems with the green seal or serial

number (usually with the green color being wrong). Finally six people also

discussed the quality of the border engraving as being an important cue.

While these comments are generally similar to the ones given for each bill,

they do indicate that people used a set of rather systematic cues in trying to

distinguish counterfeit bills from genuine. Without any training, other than

that in general knowledge, they focused on cues related to the quality of the

engraving, particularly in the portrait and in the border, as well as on fine

gradations in shading and color. They also were aware of problems of intentional aging and looked for inconsistencies in wear relative to apparent age.

The only misleading, but frequently cited cue was that of feel. As mentioned

earlier, genuine bills were frequently noted as feeling wrong. Clearly,

people’s expectations about the feel of money were different from how money

actually feels. This may, of course, be related to the worn characteristics

of many of the bills, although many negative comments about the feel of new

bills were also recorded. Nevertheless, the comment data in general indicate

44
that people noticed rather fine variations in bill quality, and used these as indicators of counterfeitedness.

Table 6 presents data on the amount of experience and training that participants

reported having with counterfeit and genuine money. With the exception of

summer employment, no person had spent much time as a cashier or store clerk.

Most people reported being reluctant to carry large amounts of cash, and some

unfamiliarity or even distrust of larger denominations. Only one or two people

had any familiarity with the Secret Service publications on counterfeits,

although a number of people had taken the Bureau of Engraving and Printing

tour. It appears to be reasonable to conclude that participants in the pilot

study were relatively inexperienced with cash handling in general, and with

counterfeits in particular.

3.2.2 Portrait Data

During the debriefing following the conclusion of the pilot study, participants

were questioned about whose portrait appeared on specific denominations ($1,

5, 10, 20, 50, and 100). At this point, they had viewed 31 $10' s, 33 $20' s, 35 $50’ s and 31 $ 100's (3 to 7 bills being counterfeit in any one denomination

- but all bills being accurate in the use of the correct portrait for the

denomination)

The data indicate that 85.7 percent of the participants correctly identified

George Washington on the $1, 61.9 percent correctly identified Grant on the

$50 and Franklin on the $100, and 52.4 percent identified Lincoln on the $5,

Hamilton on the $10, and Jackson on the $20. It should be noted that participants

did not view any $l's, $2's, or $5's in the study. Jefferson, whose potrait is

actually on the $2, was mentioned as being on the $5, $10, or $20 by 2-3

participants. The percentage of "don't know" responses ranged from a high of

33 percent of the $5 to about 24 percent for the $10, $20, and $50 bill, to

10-15 percent for the $1 and the $100.

These data suggests that participants were very familiar with the $1 bill and

its design characteristics. It is also possible that, since their comments

indicated lesser familiarity with the $50' s and 100's, they may have paid more

attention to those bills, so that they had a slightly higher percentage of

correct recognition for the portraits on those bills. It would be interesting

to ask a random sample of 21 observers to identify the portraits for each

denomination so that the problem of familiarity due to the experiment itself

could be avoided.

3.3 Spectroradiometric Data

The possibilities for physical measurement of real and counterfeit currency

present an embarassment of riches. Of particular interest are the spectral

reflectances of paper and ink, as well as the sharpness of printed details.

To compare a collection of notes, summary measures are desirable, particularly

those which relate to human visual responses

45
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47
In the present study, spectral radiance was measured under a well-controlled

source, at 3-8 spots on each note, and summary measures were computed from

these spectral radiance functions, including the CIE chromaticity (x, y) and

chromaticity in the CIE 1960 Uniform Color Space (u, v). The spectral radiance of a standard white surface was measured from time to time under identical conditions, so that spectral and luminous reflectance could be computed

referred to the actual laboratory light source. While an ideal analysis would

start with the spectral reflectance data and determine the chromaticities of

papers and inks under a standard light such as an equal energy illuminant or Illuminant C, this was not done in the present case, because of equipment

limitations. Data presented are all referred to the laboratory light, which

is markedly yellower than Illuminant C or an equal energy light. This allows

comparison between bills in this experiment, but not with data obtained using

another source as the reference standard.

3.3.1 Measurement Data for Counterfeit Bills

The spectroradiometric data were taken for all counterfeit bils obtained from

the Secret Service. Data for each of the measures taken per bill were tabulated

for x,y coordinates and u,v coordinates as well as luminance. The u,v data

were then graphed into a Uniform Color Space plot for each of the spots measured

on the bills. Figure 3 presents a graph of the Uniform Color space showing the

region of interest for currency measurements. All subsequent chromaticity

measures are graphed in a portion of this space.

Table 4 of the Appendix presents CIE chromaticity data in both x,y and u,v

coordinates as well as luminance values for the counterfeit bills actually used

in the pilot study.

Figures 4 to 7 present the chromaticity data and reflectance data for all 108

counterfeit bills as a function of rapidprint number (an identifier used by

the Secret Service). Table 4 of the appendix provides both rapidprint and

serial number identification for each bill. These figures include the 22

counterfeits used in the pilot study. Figures 4 to 5 present data for the

$10 f s and $100's while figures 6 to 7 present data for the $20’s and $50's.

The chromaticity data are graphed in the 1960 CIE Uniform Color Space (u, v)

which allows ready comparison of perceived differences in color appearance

measures. The reflectance data are presented as a function of Munsell Value,

again to allow comparison of perceptual differences in reflectance.

Figure 4 presents chromaticity data for 3 spots measured on counterfeit $10

and $100 bills. These spots are: (4a) the white areas near the seal; (4b)

the green Treasury seal itself; (4c) and the black letter for the Federal

Reserve Bank. Examination of figure 4 shows that only the data for the green

seal (4b) have much variability in chromaticity. Figures 4a and 4c, of course,

represent black and white areas of the bill, where less variation in chromaticity might be expected.

Means and standard deviations were also calculated for five spots, including

the front lathework and the portrait, and are presented in table 7. Table 7 presents data for $10's and $100's first and for $20's and $50's second. The

48
O

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COa o

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49

Figure

3.

Uniform

Color

Space

Showing

Area

of

Interest

for

Currency

Chromaticity

Measurements.
u

Figure 4a. Chromaticity data for white area near seal.

U

Figure 4b. Chromaticity data for green seal.

U

Figure 4c. Chromaticity data for black Federal Reserve letter.

Figure 4. Chromaticity data for three areas for counterfeit $10' s and $100 s presented in 1960 Uniform Color Space.

50
Variability of Reflectance

Cf) %

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duiiL

3

5

**

t 1 J—L 1 1 J 10 20 30 40 50 60 70

Rap i bpr i nt Number

80 90 100 110

Marker = + Spot = 1 (Descrip = bk. lathe).

Marker = X Spot = 2 (Descrip = frt. lathe).

Marker = Box Spot = 3 (Descrip = white).

Marker = Octagon Spot = 4 (Descrip = green).

Marker = Triangle 5pot = 5 (Descrip = bl .&. green)

Marker = Bow tie Spot = S (Descrip = bl . &. wh I te)

Marker = +, Spot = 7 (Descrlp = portrait).

Marker = X, Spot = 8 (Descrlp = blk. letter).

Figure 5. Reflectance of measured spots on counterfeit $10'

$100, s presented as a function of rapidprint number and approx

imate Munsell Value.

and

51
u

Figure 6a. Chromaticity data for white area.

o,3o n i i i I i i i i i i i i i l i l i i i i 0.15 0.20 0.25 0.30 0.35 0.40 0.45

u

Figure 6b. Chromaticity data for green seal.

U

Figure 6c. Chromaticity data for black Federal Reserve letter.

Figure 6. Chromaticity data for three areas for counterfeit $20'

and $50 s presented in 1960 Uniform Color Space.

52
Variability of Reflectance

^*) O CO O O

° ° <?° 0 gf-a «g o

S Se DO * —

" °

** !.“ a*® y. ** «

* a a o o *

* *** a * 2

_ ><*

10 20 30 40 50 50 70 Ropldprlnt Number

80 90 100 110

Marker = +* Selection: 5pot equals

Marker = X, Selection: Spot equols

Marker = 3ox, F Selection: Spot equals

Marker = Octogon/

Selection: 5pot equals

1 (=lathe.bk/ consistently). $20’s & S50's.

2 (=lothe.frt, cons I stentl 4 ] . S20‘s 4 SSZ's.

4 (=qreen* consistently). S20^s i S50's 3(=whlte). S20‘s & 53's.

Figure 7a. Reflectance of lathework, green seal and white area.

Variability of Reflectance

O

“ 5|

4E- W«v *“0 *4* •4.4*

‘vv«r *.4 4

4 4 . 4 °0‘ ’ « 4

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1

* 4.4 V =4 * ^ -4

0 0**»

10 20 30 40 50 60 70 Rapidprint Number

80 90 100 110

Mor^er a +. .... Motch condition: Demon 3 20 (Oescrlp 3 bl.&.greenl.

Observe thot Spot 5 on $20 differs from Soot 5 on $50. Marker = X Match condition: Qenom = 50 (Descrip - portrait). Marker = Box Motch condition: Demon = 20 (Descrlp = bl. 4. white). Note thot Spot 6 on the $20 differs from Spot 6 on the $50. Morker = Octoqon Motch condition: Demon = 00 1 Descrlp - bl<. letter.. Marker = Triangle Motch condition: Spot =7 (Descrlp “Portrait).

Marker = Bow tie Motch condition: Spot = 3 iDescrlp = b I c. letter 1

Figure 7b. Reflectance of portrait, black letter, and black and

green areas of green seal.

Figure 7. Reflectance of measured spots on counterfeit $20' s and

$50' s presented as a function of rapidprint number and approximate Munsell value.

53
Table 7. Mean Chromaticity Values in Uniform Color Space for

Selected Spots on Counterfeit Bills

7a. Values for Counterfeit $10's and $100’s

Location Mean Standard Deviation

Front Lathe u = .260 0.004

v = .355 0.010

White u = .262 0.006

v = .357 0.001

Green u = .204 0.020

v = .362 0.002

Portrait u = 0.260 0.005

v = 0.360 0.001

Black Letter u = 0.261 0.004

v = 0.355 0.001

7b. Values for Counterfeit $20 T s and $50*

Area Mean Standard Deviation

.Front Lathework u = 0.258 0.004

v = 0.355 0.009

White Area u = 0.261 0.005

v = 0.357 0.001

Green u = 0.201 0.018

v = 0.366 0.321

Portrait - $50 ? s u = 0.258 0.004

v = 0.355 0.009

Portrait - $20's u = 0.260 0.003

v = 0.355 0.001

Black Letter $50*

u = 0.260 0.004

v = 0.354 0.009

Black Letter $20'

u = 0.261 0.003 v = 0.355 0.008

54
u,v coordinates are virtually the same for all spots, except for the green one where the u value has shifted further toward green. There is also much greater

variability for this spot. It is possible that the observed variation in

chromaticity of the "green seal" in the u direction may be largely a measuring artifact, while the seemingly smaller variation in the v dimension is

probably significant. This variation suggests that counterfeiters permit a wider variation of their green in the blue-yellow dimension than does the

Bureau of Engraving and Printing. The data suggest further that counterfeiters

have reasonable control over the chromaticity of the black and white areas of

the bills, both between and within bills.

Figure 5 presents the reflectance data for the counterfeits. Greater variability

for these measures should be expected, particularly for the reflectances of

the black and the white areas. The data are presented as approximate Munsell

Value as a function of rapidprint number. Munsell Value is a measure of perceived brightness; a perfect white has a Value =10. The variations in absolute

reflectance relative to the 695 fL of the reference standard are too small to

be readily meaningful. The Munsell Value Scale, however, translates these

absolute variations into ones perceived by the eye, which is very sensitive

to small variations in luminance. This scale thus is a better representation

of the variability that is actually seen. Accounting for the eye’s nonlinearity

in this way gives the most meaningful measure of how much the bills vary in

perceived reflectance. The data in figure 4 for $10’s and $100's show considerable variation. The white spot (square) has the highest reflectance,

while the black letter (x) has the least.

Means and standard deviations of Munsell Value were calculated and are presented

in Table 8. Table 8 presents the reflectance data for $10’s and $100’s first

(8a) and $20 ’s and $50 ’s second (8b). The white and black areas have the

greatest variability in reflectance while the green has the least.

A similar pattern of data occurs for the $20’ s and $50 ’s shown in figures 6

and 7. Means and standard deviations for the chromaticities $20' s and $50 ’s are presented in table 7b. As with the $10’s and $100’s, the green spot differs

most in variability in chromaticity. The data are very similar to those for

the $10's and $100’s.

Figure 7 presents reflectance data for the counterfeit $20 's and $50 ’s. As

in earlier measurements, the white area has the highest reflectance, while the

black letter has the least.

Comparison of the data given in tables 7 and 8 indicate that the $20' s and

$50 ’s differ somewhat from those for the $10 ’s and $100 ’s. The measurement of

the overall mean Value is lower for the front lathework, while the mean for

the $20 ’s and for the $50’s brackets that for $10's and $100 's in the portrait

area. For all denominations, measurements for a given spot typically have a range as much as a whole value unit, with the range being even larger for the

black letter.

55
Table 8. Mean Reflectance Data for Munsell Value for

Selected Spots on Counterfeit Bills

8a. Values for Counterfeit $10 ' s and $100 '

Location Mean Standard Deviation

Front Lathe 4.94 0.599

White 7.82 0.886

Green 5.12 0.526

Portrait 4.83 0.634

Black Letter 3.62 0.700

8b. Values for Counterfeit $20’s and $50’s

Location Mean Standard Deviation

Front Lathe 4.62 0.553

White Area 7.93 0.502

Green Seal 5.11 0.620

Portrait - $20*

4.47 0.544

Black Letter $20's 3.54 0.534

Portrait - $50’s 5.28 0.438

Black Letter $50’s 3.70 0.874

56
These data appear consistent with participant comments about greens being wrong

and blacks being greyed for the counterfeits. The differences are subtle,

however, with the majority of the counterfeits having fairly low variability in

chromaticity and reflectance.

3.3.2 Measurement Data for Genuine Bills

Spectroradiometric measurements were also made for a small set of genuine bills.

Bills were selected for measurement on the basis of their performance in the

pilot study. Thus, bills selected for measurement had received either a large

number of errors or a very small number of errors. In addition, only the

spots that had shown the greatest physical variability for the counterfeit

bills were measured. These spots were: the white area near the portrait; the

black area of the Federal Reserve letter; and the green of the Treasury Seal.

Figures 8 and 9 present both chromaticity data and reflectance data (in Munsell

Value) for the three spots measured on genuine bills. Data for genuine bills

are plotted as a function of new number - an arbitrary identifier. Table 5

of the appendix provides both serial number and new number identifiers, as well as the raw data for each bill. All denominations are plotted on each

graph. In figure 9, reflectance is plotted first for all bills (8a) and then

for each of the three wear conditions (figure 8).

Table 9 presents data on means and standard deviations for Munsell Value for

genuine bills for all four denominations. Because it was thought that wear

conditions might result in different Munsell Value, summary data are presented

first for each condition and then for all conditions combined.

Data in Table 9 for genuine bills can be compared with those in Tables 10.

The standard deviation for both u and v is smaller in all cases for the genuine

bills. The mean chromaticity coordinates are very similar, except that mean

values of u for the genuine green seal is shifted slightly to the left toward

green, away from yellow. While this may indicate an intrusion of white into

the measurements of the counterfeit bills, it may also indicate a genuine

difference in the green seal between the two types of bills. This suggestion

is reinforced by the great similarity between the chromaticity values for the

other spots for both counterfeit and genuine bills.

The reflectance data for both types of bills can also be compared using

Tables 8 and 9. This comparison indicates that for the white area, the mean

reflectance Value for all counterfeit bills is lower than the mean Value for

"good" genuine bills, and is even slightly lower than the mean Value for "bad"

genuine bills. In addition, the standard deviation is higher particularly for

counterfeit $10 , s and $100 ’s. For the black area, the mean Value for the

genuine bills is lower for all mean conditions (2.95 vs about 3.6) and much

lower for "good" genuine bills. Again, the variability is lower for genuine

bills

For the green seal, the reflectance data for the genuine bills are also lower,

indicating a more saturated green than on the counterfeit bills. The counterfeit

Treasury seal is lighter than that for even the least worn genuine bill. Again

the variability is greater for counterfeit bills.

57
u

Figure 8a. Chromaticity data for white area of genuine bills.

U

Figure 8b. Chromaticity data for green seal of genuine bills.

U

Figure 8c. Chromaticity data for black Federal Reserve letter on genuine bills.

Figure 8. Chromaticity data for three areas of genuine $10's, $20's, $50’s,

and $100’ s presented in 1960 Uniform Color Space.

58
Variability of Reflectance

10 20 30 40 50 60 New Number

70 80 90 110

Genuine

Marker = X, Geoj I nm Marker = 8< Gersjine

File • REPL.5PT3. No watch required.

noTe5» S100‘s» 50's* 20‘s ond Id's. Unprlnted oreo near portrait. * “ ~ 'No watch required.

note*. S103 ' s. 50’s. 20'* end )£'s. Gri

i*. File = RERL.5PT0, No wotch required. note*» *100 *» 50'*# 20'* ond 10 ' s. 31ock of Federal Reserve I etter

Vhlte Intrusion posslbl

Figure 9a. Reflectance of white area, green seal and black

letter for genuine bills for all wear conditions combined.

ai 4|

*» i

*s

10 20 30 50 60 New Number

70 80 90 100 110

n*rk*r . Ckrtooon. Fl 1. REHL.SPT4. h«ph condition; Cond - 1 tlWscrlp - grssrt bwsjlne notes. $100' s» SB's. 2B's ond IBs. 3re«n of Treesung seal . Vhlte Intrusion posslbl Narxw s Trlnla. File « REtL.SPT*. hatch condition; Cond = 2 IBascrlp = gr«m

. Bow t7«. Fl 1. . BEBL.SPT*. hatch crowlltlon; Cond - 3 (Dascrlp • 5r*«n Figure 9b. Reflectance of green seal for each wear condition.

31-l2l‘

10 20 30 40 50 60 New Number

90 100 110

Genu I Marker • Marlew

Genu 1 1 Marker • Marksr «

Qctogon.

ne notes* Trlangla

Bow tie.

«•* File

«• notes*

X* File

Box* Fl

File - RERL.SPT3* Hate* condltloni Cond - 1 C Descrip - ^*lte). 5100's* 50'** 20's ond 10's. Unprlnted oreo neor portrait.

, File « REPI_.5PT3* Match condltloni Cond * 2 l Descrip vhlte). File - RERL.SPT3, Match condition! Cond - 3 t Descrip - white). RERL.SPT0. Match condition: Cond 1 ! Descrip « block

S100's. 50'*. 20's ond 10's. Block of Federal Reserve letter. RERL.SPT8* Match certdltlonx Cano « 2 IDescrlo - blocs

i x REPL.SPT8. Match ccwdltlon: Cond = 3 l Descrip - block Figure 9c. Reflectance of white area and of black letter for

each wear condition.

Figure 9

presented as

Reflectance

a function of

of measured spots on genuine bills

New Number and Munsell Value.

59
Table 9. Chromaticity and Reflectance Data for a Selected Set of

Genuine Bills

9a. Chromaticity Data

Area Coordinate Mean Standard Deviation

Treasury Seal - Green u 0.179 0.020

V 0.364 0.002

White Area u 0.260 0.004

V 0.357 0.001

Black Letter u 0.258 0.003

V 0.354 0.001

9b. Munsell Value

Area Coordinate Mean Standard Deviation

White Area Good 8.29 0.087

Bad 7.95 0.201

Very Bad 7.44 0.526

All 7.88 0.478

Black Letter Good 2.74 0.330

Bad 2.95 0.425

Very Bad 3.15 0.347

All 2.95 0.397

Green Seal Good 4.96 0.353

Bad 4.74 0.386

Very Bad 4.67 0.457

All 4.79 0.408

60
Counterfeit bills that had many comments about "wrong color” included:

0436D, 1381A, 3271C, and 4051D. These bills had higher "u” values for the

green seal than the mean for the genuine bills (e.g., 0.222, 0.239, 0.219,

and 0.232, compared with 0.179). They also had higher mean reflectance in

the black area (3.62, 3.54, 3.70 vs. 2.95). The physical measures thus

indicate real, observable differences in chromaticity and reflectance.

The difference in reflectance Value between genuine and counterfeit bills

suggest that either counterfeit quality control is particularly poor for

reflectance or that counterfeiters have deliberately aged their bills.

Certainly, anecdotal evidence suggests that this occurs frequently. Even in

the latter case, there are noticeable differences between counterfeit and

genuine bills for the black and green areas. These differences mean that the

blacks and greens are often darker on genuine bills, even worn genuine bills.

61
4 . Conclusions

4.1 Discussion of Pilot Study Data

The major result in the pilot study is that, without any specialized training,

participants were able to identify accurately the majority of the counterfeit

bills presented. Yet, few participants were able to identify all bills

accurately. Only four people identified all the counterfeits, while only one identified all the genuine bills. No person successfully identified all bills

correctly. Overall accuracy was about 79 percent for counterfeit bills and

about 74 percent for genuine bills.

Had participants been forced to make their decisions faster, in 1 second or

less, as is common during an actual currency transaction, it is likely that

they would have made many more errors for the counterfeits. To allow participants time to notice features in the bills, they were allowed to scan the

front of the bill completely. In an actual currency transaction, which occurs much more rapidly, people may realistically only look at the denomination

counter at one edge of the bill. They may not even expose the entire bill to

view. As a result, the present experimental procedure was not realistic, nor

was it intended to be a simulation of an actual cash transaction. Rather, it was intended to determine if untrained people were capable of discriminating

counterfeits from genuine currency and to elicit information about which

features of the bills were noticed.

The design of the study was such as to predispose people to find "counterfeits”

in the stacks of money. The instructions specifically asked people to look for

counterfeits rather than genuine bills, in the hopes that this would maximize

the number detected and provide more information about the cues used for

this discrimination. The result was that at least one person identified more

than 60 percent of the genuine bills as counterfeit (while identifying all the

counterfeits correctly). Yet, despite a predisposition to find "counterfeits",

only four people correctly identified all 22 counterfeit bills. (All participants

were adults, accustomed to at least a moderate level of currency handling, with

all but two being salaried employees.)

The inescapable conclusion is that the set of counterfeit bills contained some very good counterfeits which did not differ a great deal from the genuine bills.

The other conclusion is that it is somewhat difficult to discriminate counterfeits

even when sufficient time is allowed.

Nevertheless, analysis of the comment data indicates that even when counterfeit

bills were not identified correctly, people noticed different features of these

bills. In addition, they made many more comments about counterfeit bills.

Thus, even the two counterfeit bills that were identified as genuine received a large number of comments compared with actual genuine bills. This suggests

that people noticed something about counterfeits that they did not notice about

good bills. Similiarly, Stillitz found that his observers had longer reaction

times to forged notes, even when they were identified as genuine. Detailed

analysis of the comment data indicates which features of counterfeit bills

were noticed. The data strongly suggest that people noticed variations in

62
color, contrast, portrait realism, and overall engraving quality. For genuine

bills, on the other hand, they noticed printing flaws such as ink spots and

irregularly placed borders.

The data on portrait identification, while a bit surprising, can be interpreted

to support the idea that engraving qualty is an important feature of genuine

currency. Although participants accurately remembered only George Washington

on the $1 bill, they commented frequently on the lifelike quality of the face

and the way in which it stood out (or did not stand out) from its background

for all denominations. These data suggest that although people may not be

particularly aware of whose portrait is on which bill, their attention appears

to be caught by the quality of the portrait. Whether a portrait was sharp,

detailed, and lifelike seemed to be more important than whose portrait it was.

In large measure, the comment data paralleled the physical data. Where observers

commented on irregular borders, for example, they were reporting an existing

physical problem. When they noted that the ink color was wrong, the chromaticity

data for the green seal frequently differed, along with the reflectance data

for the white and black areas. Thus, the physical measures indicated observable

differences in color and lightness, which participants often mentioned.

The comments indicated relatively little reliance on known security devices such

as the red and blue threads or the points on the seal. Even though the Secret

Service (1983) considers these as good indicators of counterfeit bills, only one observer in the pilot study indicated use of these as an indicator. The other

observers stated that they looked for threads, and when they could not find

them in several bills, they abandoned them as a good cue. The comments made

during the debriefing indicated that people had a great deal of trouble finding

the threads, particularly in worn bills. In fact, participants commented

about the worn condition of many of the bills, saying that it was more difficult to detect counterfeits among worn bills. They noted further that many of

the counterfeits appeared intentionally aged, and that often this apparent

wear was inconsistent with the age of the bill.

Participants also mentioned several bill characteristics that were not as reliable indicators of counterfeiting. These included "feel”, irregular borders,

and ink heaviness or blotches. The second two are related more to print quality

control than to errors made by counterfeiters. (With very few exceptions, they

positioned the engraving properly on the paper, and did not leave stray ink

markings.) The comments related to feel, however, seem to indicate some real

misconceptions about how money ought to feel, as well as some possible real

variability within the set of genuine bills. For example, with new bills,

people often commented that they feel "too thick" or "too thin". This last

comment seemed to occur frequently for $100' s. Other comments related more to

badly worn bills and included comments related to "creasing", "bending", "feels

like it would tear easily - real money shouldn’t tear”, and "feels papery”.

These comments seemed to be made about all bills, regardless of classification.

Wear seems to create problems with accurate feel and appearance which make it

more difficult to identify counterfeits, and which may increase willingness to

tolerate deviations from good, high quality notes.

63
The data suggest that observers relied heavily on the engraving quality of the

bills. Their comments about counterfeits related primarily to deficiencies in

the quality of details, including both the portrait and the border, as well as to lack of fidelity in both color and contrast. These features functioned

generally as reliable indicators of forgeries. As Andersen (1978) pointed out,

high quality engraving continues to be a useful counterfeit deterrent. The

intaglio process allows very fine variations in detail, color, and feel that are not yet achievable by other printing processes, but that are detectable by

human observers. Participants in the pilot study clearly expected high quality

engraving, and frequently rejected bills that they felt were poorly printed,

with comments about how the government should do a better job.

4.2 Recommendations and Conclusions

The data from the pilot study and from Stillitz ’ studies provide some insight

into the problem of counterfeit deterrence. These studies suggest a number of areas in which further research might be done to increase the discriminability

of genuine bills. One of the most important is that of determining how to

increase the attention-getting value, or conspicuity, of the engraving quality

of the bill, particularly the portrait.

One of the Stillitz* ideas was to use the portrait as the sole denomination

indicator. His idea was not followed up for British currency because of a desire to use the Queen’s portrait on all notes. His idea is, however, already

partially in use for U.S. currency where a different portrait is used on each

bill. However, its effectiveness is diminished by the presence of counters at

the edge of the bill.

Since the size of U.*S. currency is currently constant and the bills are all the same color (as Stillitz recommended), the effect of varying the placement (and

number) of the numerals relative to the portrait should be assessed. A study

should evaluate the effectiveness of locating two numerals centrally, on each

side of the portrait so that the user is forced to look at the portrait when

trying to determine the bill’s denomination. At the moment, it is too easy to

determine denomination just by looking at a small fraction of the edges of the

bill. (Counterfeiters take advantage of this tendency by "raising" the bill - pasting numerals from higher denominations on to notes of lower denomination.)

The rest of the bill, including the all-important portrait can remain

obscured, so that the security value of the engraving quality is lost. A

research project should be designed in which the position of the numerals on the bill and the security engraving is manipulated, and reaction time, comprehension, and salience are assessed.

At the same time, the effects of greater variation in portrait appearance

between bills should be assessed. Currently, all bills contain portraits of

historical figures. Comments by the participants in the pilot study indicated

that they were familiar with the appearance of Washington, Jefferson, Franklin,

and Lincoln, but less so with Grant, Jackson, and Hamilton. The comments and

portrait identification data suggest that some of the portraits do not have

64
the immediate recognition that the Queen has on British notes. The effects of

varying historical period and using different styles of portraits (as with

current U.S. coinage) should be determined, to assess the effects of familiarity

with the portrait on forgery recognition. Another important area for further

research is that of color. People are capable of very fine color discrimination

and accurate color matches, while copying machines typically are not as accurate

in reproducing these colors. Numerous comments in the pilot study related to

yellowness, both of the paper itself and the green seal and serial numbers.

People clearly noticed small color variations. Since Stillitz suggested that

varying color between denominations is not a good idea, one might increase the

number of colors slightly on all bills. The same set of colors should be used

on each denomination. This would allow one to take advantage of the difficulties

in reproducing similar colors, yet avoid the problem of characterizing denomination by color. It would also take advantage of the human visual system's

ability to make fine color discriminations. Another set of studies could

assess the effectiveness of varying color, or colors, for the set of bills

under a variety of light sources and light levels. In addition, the effectiveness of specialized light sources for detecting a particular color used as a security device should be assessed, as should variation of security devices

themselves

Printing depth and paper quality is another area in which additional research

is needed. Feel of the bill was a major criterion used by participants in the

pilot study, along with color, line quality, and overall appearance in detecting

counterfeits. For example, participants often commented that bills felt wrong

for the age they appeared to be, or that bills were too limp or too thin.

Stillitz also found feel to be a reliable sense for discriminating between

genuine and forged notes. He determined as well, that people could reliably

detect small differences in printing depth. Touch, along with color, is a sensory dimension in which people are capable of making small and accurate

discriminations. As a result, the feasibility should be assessed of altering

the feel of currency by increasing printing depth. Genuine notes would then be

more discriminable in feel from photocopied forgeries. However, this change

would require greater control over the wear of bills in circulation.

Finally the effects of increasing public awareness of counterfeits need to be

assessed. Data from the pilot study indicate that when people are sensitized

to the possible presence of counterfeits in a stack of bills, they find them,

even when the bills are not actually forged. Stillitz also found that British

observers would reliably find forgeries in a stack of genuine notes. These

"forgeries" often contained real printing flaws that slipped past the quality

control in note production. Yet, on the other hand, data from the pilot study

indicate that not all people can find all counterfeit bills in a stack of money.

Furthermore, Stillitz found several situations in which people did not even

count their money, much less find the forgeries in it. As a result, people

concerned with currency must be aware that, when sensitized to the possible

presence of counterfeits, people become very aware of real printing flaws, and

will find "counterfeits". They will also take more time to examine their money

and decrease speed of currency transactions. This problem must be balanced

against current casualness in money handling, in which money is assumed to be

65
genuine, and so failures in quality control are not identified. The problem

is further exacerbated by worn currency in which some of the features of quality

engraving are blurred as the bill ages. It is relatively easy to separate a new, genuine bill from an aged counterfeit. Yet, there are enough worn bills

in circulation that it becomes worthwhile for counterfeiters to deliberately

age their bills to camouflage them.

The present pilot study has suggested that while people can recognize counterfeit U.S. dollars, they do not do so with total accuracy, even in a situation

designed to maximize detection of counterfeits. Research by Stillitz and

other researchers (DeValois and DeValois, 1980), has pointed out that people

are capable of very fine color, line quality, and tactile discriminations.

Both the pilot study and Stillitz’ research have demonstrated that people are sensitive to and will notice bill qualities resulting from good engraving and

careful printing. These capabilities should be researched further to aid in

developing effective counterfeit deterrents. Stillitz has emphasized, however,

the need to increase the amount of time spent in inspecting the bill during

normal currency transactions so that counterfeit deterrents and engraving

quality are noticed. The present study reinforces this assertion, while

recognizing that the costs of slowing down currency transactions must also

be assessed.

66
5.

REFERENCES

Anderson, G. Banknotes - Principles and Aesthetics in Security Graphics.

Copenhagen: Danmarks Nationalbank Banknote Printing Department, 1975.

Baker, E. Spotting the Fakes - Forgeries and Counterfeits , Chicago, IL, 1980.

Cooke, D. C. How Money is Made . New York: Dodd, Mead, and Company. Rev.

Ed., 1972.

DeValois, R. L. and DeValois, K. K. Spatial Vision. In Annual Review of

Psychology . 1980, 31, 309-341.

Harshe, B. How to Detect Alered and Counterfeit Coins and Paper Money . Orlando, Florida: House of Collectibles, 1978.

Jeffress, Lloyd, A., Stimulus-Oriented Approach to Detection, J. Acoustical

Society of America , 1964, 36, 766-774.

Torres, D. A. Criminal Patterns and Counterfeit Currency. Journal of Police

Science and Administration . 1980, 31, 309-341.

U.S. Secret Service. Know Your Money . Washington, D.C. U.S. Government

Printing Office, 1983.

Washington Post Magazine , The Coloring of Greenbacks (by Margaret Carlson),

February 12, 1984, pp. 8-21.

Wright, W.D. The Measurement of Colour . New York: Van Nostrand Reinhold Co.,

4th Ed., 1969.

Wyszecki, G. and Stiles, W. S. Color Science . NY: John Wiley & Sons, 1967.

Documents prepared by Prof. Ivor Stillitz for the Bank of England. Available

from the Bank.

1. University College Banknote Design - I, 1970-1971

2. University College Banknote Design - II, 1971-1972

3. University College Banknote Design - III, 1972-1973

4. University College Banknote Design - Part I, 1975-1976 - Summary

5. University College Banknote Design - Part II, 1975-1976

6. Review of the Perception Research - 78-79, December 1979

7. Comments on the Introduction of New Notes, 30/6/80

8. Comments on the Ergonomics of Banknote Design, 19/6/80

9. Preliminary Study of the Perception of Value in Banknote Elements - 80/2,

July 1980

10. Fronts and Backs of Notes - 78/1, August 1978

11. Psychological Aspects of 3 Security Devices, September 1978

12. Numerical Location on Notes - 79/1, July 1979

13. Preliminary Study of Salience of Note Size as Denomination Cue - 79/2,

67

APPENDIX

Table 1. Instructions to Participants in Counterfeit Pilot Study

We are interested in how people detect counterfeit money. The U.S. Treasury

carefully designed bills to be difficult to counterfeit, but a large number of

fake bills are passed each year.

We want to determine what people actually notice when they examine paper money,

so you will be asked to look at some real and some counterfeit money and tell

use what you observe about these bills. We are interested in the ability to

identify counterfeit bills and want to know what bills you think are counterfeit

and what features of these bills you notice. Although this is not a real moneyhandling situation, plese imagine yourself having received these bills in a cash transaction. We will limit viewing time accordingly.

We will give you 3 stacks of bills with about 30 bills in each stack. Each stack

may contain all types of bills. We will give you three stacks of bills consisting

of ten, twenty, fifty, and one-hundred dollar bills in different stages of wear. These bills represent a mix of real and counterfeit money.

We want you to examine only the front of each bill and decide if it is real or counterfeit. Please examine it against the background of the table. When you

have finished, please hand the bill to the experimenter, and say whether it is

real or counterfeit. Please give the reasons your decision, telling us what

you noticed about the bill. We would like you to go through one stack at a time, and then take a brief rest. We will give you about ten seconds to examine

each bill and tell us about it. We will be writing down your impressions about

each bill.

Describe what you noticed when examining the bill, and how you decided. When

you finish, you will be given the next stack of bills.

As you go through the bills, please keep the following questions in mind. We

will be discussing these at the end of the experiment.

Were any features especially important in making your judgement?

If so, what were they?

Were they different for different bills? If so, in what way?

At the end of the study, we would like you to indicate which features you found

most important about those bills you identified as counterfeit. If you can,

please define the features that you used. Start with the most important

characteristics of the bills. (The experimenter has recorded the features that

you mentioned, and can tell you them.)

How noticeable were those features? Easy to detect? Hard to detect? Please

use a scale of 1 to 5 with 5 indicating the most difficult to detect.

1-1
Table ,1 - (Continued)

Did you follow a particular procedure (pattern) for all bills? Did you change

cues as you went along? Did you notice any general features about the bills?

Did you find it easier to detect counterfeit as you went along? If so, why?

General Comments.

How you had much experience handling cash, in a previous job, for example?

Ever see a counterfeit bill?

Do you examine paper money to see if it is counterfeit?

Were you trained to check? How?

In the task, did you follow any previous training, or did you make up your

own procedure? Which was more useful?

Have you read anything put out by the Treasury (or others) on how to

detect counterfeits?

Do you have any questions or comments?

Thank you very much for your participation.

1-2
APPENDIX

TABLE 2. COMMENTS FOR EACH SERIAL NUMBER

COUNTERFEIT BILLS

0324E

Paper quality

Engraving not clear

Xerox looking

Ink looks wrong

Printing looks wrong

Very yellow

Wrong color all over

Uneven fading

Contrast on green seal

Portrait strange

Paper funny

Gold areas (where tape had been) look fake

Contrast too weak (dark not dark enough)

Poor quality printing

Portrait, lathework all bad

Black and green also bad

Stamped on too dark, not legible

Bad paper

Almost a xerox, poor graphics

Long creases, real poor

Don' t like his face

Not clearly printed - not precise

Lack of detail on border, too much shadow under lettering

Too yellowish in white areas

Paper feels wrong

Color off in paper and printing

Hamilton and background not distinct, too dark

Ink color

69 bi ll--di f f erent kind of paper

Faded wrong; money doesn' t usually fade. Fuzzy

0 3 9 5 D

Printing not sharp; too light

Paper wrong

Black ink is wrong color

Paper questionable

Portrait weird

Print in border is wrong

Color not right overall
Portrait not well done

Irregular points on green seal (not sharp)

Very obvi ous--looks like photocopy

Lathework, portrait dead

No threads

Looks bad overall

Poor counterfeit; grayish blacks, washed out greens

Poor central image quality

Placement of picture funny

Picture and writing look funny - something missing

Portrait not precise

Paper texture wrong

Looks funny

Printing is f ai nt

Color is wrong

Looks real

Ink dim

Reservations about 50' s embedded in border, seems overkill

0 4 3 6 D Green numbers not sharp; seal also

Paper wrong

Paper color aged wrong

Feels wrong

Little threads missing

Wonder why old and taped??

Colors fade, but ten didn' t - ( Not worn enough)

Paper funny

Date too old to still be around

No fibers

Irregular trimming of edges

Paper wrong

Background too filled in on portrait

Lathework poor

Looks counterfeit

Bad paper

Blatant, smeared image and background

Yellow aging of paper

Creasing wrong

Feels different

Not as embellished on sides

Peculiar greenish white background

Is too dirty

Too brown

Color funny

Fine lines lack detail

Seal strange and lighter

Coloring is strange

Crooked on paper

Message at top and at bottom incorrect - "Will pay to bearer on

demand" ??

2 - 2
Dark parts too dark

Portrait fuzzy

Overall color fuzzy

Bill has been handled many times

0759*

Jackson doesn' t look good

Shading is not good (contrast)

Paper feel wrong

Dirty

Star??

Feels too smooth, too slick

Face looks wrong, not like Jackson

Feel of paper wrong

Paper texture wrong

Too much mottled area (smudges)

Paper texture wrong

Contrast in portrait wrong

Not enough fibers

Blunt points on seal

Jackson looks different

General appearance wrong

No fibers

Paper wrong

Not intaglio

Green is off

Obvious dirt is faked

Ink off creases

Black printing bad

Darker stamp of border

Dirt funny on background

Obvious poor counterfeit, xerox quality

Paper doesn' t feel like the old worn bill it looks like

Feels wrong

Background has been through the mill, but the bill is not soft

Enough

Printing is too dark--too black

Paper texture wrong

Color of white area wrong, border too dark

Whole bill just looks wrong

Feels wrong

Printing too dark

Eyes and other graphics strange

Overall contrast poor - printing not distinct

Discolored - paper background is dingy

Hard, nothing real obvious

1 2 9 2 A

Paper bad

Yellowi sh

2-3
Lines not sharp

Ink and printing too faint

White color wrong

Paper feels wrong

No threads

Paper not smooth enough

Portrait detail not as distinct

Numerals (denomination) over seal are too dark

Too dark color overall

Green tint overall

Print quality--not sharp

Blunt and uneven points on seal

No f 1 bers

Franklin looks different

Poor quality printing

Flat. Doesn' t stand out ( as intaglio should)

Paper also wrong in color and feel

Bad paper; scotch taped

Paper wear, fold characteristics bad

Too worn for a $100

Lettering of usa doesn' t look right at top

Dark areas too dark

Line quality poor

Paper feel and tint

Detail good

1 381 A

All off-color

Detail poor - not sharp

Darkness funny

Paper wrong

Yellowing of paper

Feels waxed

Looks like museum money

Color and grain wrong

No threads

Unusual color/ overall--too yellow. Faded strangely

Yellow color of paper

Overall color wrong

But also the green seal and serial # color wrong

Paper appearance poor

Printing line quality poor

Poor background color, not enough white

Paper feels funny

Grant looking at me--looks wrong

Poor quality printing

Lousy. No lathe work

Green ink wrong

Portrai t flat

Paper wrong. Everything wrong

Feels wrong; not like money

2-4
Federal reserve note writing looks much smaller than it should be

Horrible counterfeit. Overall poor definition of ink

Paper bad color, looks like high sulfur content

Creases, funny, but ink dominant characteristic

Kind of yellowish compared with most money

Brown color wrong

Dark too dark

Detail not as fine as on real bill

Yellowish coloring

Overall color wrong, even though old

Not enough green

Color doesn't look quite right, money doesn't usually lose its

Color

Play money - paper wrong color and feel

Printing too dark

Color overall

Feels ok, but thought that 77 series had different signature

2 2 3 6 D

Li nes not clear

Ink bleeding - all one shade of grey

Black seems wrong, ink color poor

Color of paper wrong

Paper feels wrong

Paper feel wrong

Threads missing

Paper too thick

Print too dark

Paper too hard

Paper quality

Printing is different - too black (dark)

Details not sharp especially in border

Uneven points on seal

No fibers at all

Engraving not clear

Everything, lathe, portrait bad

Green color bad

No threads

Blacks not right

Darker stamped, feels right; dark too dark.

Obvious counterfeit. Poor ink quality in image and counter

Entire border poor

Paper creases

Funny feel

Big 5 0

' s funny

Detail and clarity lacking in border

Dark background so strong

Detail definitely gone

Black too dark

Printing is too dark--too black

Border too dark

2-5
Wonder if Grant usually faces that way

Border too dark (play money)

Coloring off, looks black and white

Lacks green color

Feels different

Different paper

Dark areas too dark

Green is wrong

Black is wrong. Color wrong

Have trouble with Grant. He has different expressions on

different bills

3271C

Everything wrong - all color

Paper wrong

Pri nti ng wrong

Paper wrong

Color changed wrong over time

Bill seems longer (horizontally)

Color wrong

Worn, but portrait still has good contrast

Print is too dark

Color: an old bill shouldn' t be so clearly printed

Printing quality poor, especially portrait

Green seal screwy, all messed up

Face looks different

No fibers

Looks phony, almost handrawn

Ink color for serial number and seal wrong

Portrait lathework wrong

Poor quality paper

Head smaller in circle

Stamped on; engraving poor; not as legible

Xerox job; engraving not there

Washed out blacks and greens

Yellow sulfur color

Creases no good

Older bills different feel; different finish on paper;, waxy,

Hard, too much so, for apparent age. , Peculiar color. Too putrid green

Printing not precise - margin uneven

Printing is too dark

Color is funny

Yellow

Paper texture wrong

Print not clear (low quality appearance).

Ink wiping off, green lettering faded more than rest of bill

Printing not distinct

Paper wrong

Printed too dark

Color wrong

Portrait wrong - shadows, other

2-6
3691 H

Lines bad - black gradations; but has threads

Face not clear

Photocopy appearance

Uneven points on seals

Washed out engraving

Fake threads

Poor engraving quality in portrait

Lines overly bold - too prominent

Blackness in border lacks crispness

Green color wrong

Portrait, other wrong

Paper feels too stiff and heavy

1969? Correct date?

Paper feels funny, not like money

Ok despite holes

Black seal not as sharp as should be

Not sure why uncertain

Quality better; heavier paper

Not even in contrast - one side of border looks darker

Greenish tint funny

3 7 5 2 F

Like copy; paper wrong

Color poor

Detail poor

Feels weird

Face strange

Portrait distorted

Threads missing

Portrait and background blend together

Paper feels funny

General appearance wrong

Portrait is wrong (not specific)

Bad points on seal

Hamilton looks funny, eyes strange

Poor quality printing

Terrible. Numbers lined up wrong

Ink color, blacks wrong

Paper wrong

Background of portrait wrong,

Paper cheap and thin

Bad job; central image is blurred, poor contrast, with

Hi ghl i ght s Fuzzy paper

69 bill; facial f eatures--li ps & nose too pronounced

Feels thin. Awfully old

Portrait not clearly done - not precise

Border detail looks wrong

poor

2-7
Picture doesn' t seem to have right shading, not sharp image

Feels phoney - seems to have been washed, is limp

Hamilton; background dark and portrait wrong

Wonder about check # (or plate ft) Paper and ink color wrong

Portrait graphic wrong

3 8 0 7 A

Franklin looks bad. Lines not clear

Paper feels grainy

Ink faint, not black enough

Paper feels wrong - too stiff, too smooth

Overall impression wrong; partly color

Printing different. Contrast of seal poor

Gray and green funny

Overall contrast also poor

Paper funny

Paper wrong

Portrait looks different

Uneven points on black seal

No fibers

Franklin' s nose looks like elephant trunk

Portrait, lathework wrong

Numbers ( green) and seal--wrong

Smooth feeling

Imitated threads - too straight

Franklin looks different; mouth, pin on coat. Quality wrong

Poor definition of image

Gradation, contrast, & highlighting poor in image and in border

Size. Too small in width

Paper texture wrong

Color is fuzzy

Not a sharp image

Looks like wrong size

Printing not right on portrait

Paper wrong

Graphics not sharp

Same hard feel as previous bill (a counterfeit)

4 0 5 1 D

All lines wrong

Paper feel

Color wrong

Yellowness of paper wrong

Feels wrong, like newspaper

Color wrong

Paper feels hard

Color wrong

Poor contrast in seal and value numbers

Poor contrast in portrait

2-8
Background too dark

Paper feels wrong

Not printed clearly; poor line quality in border design

Green tinge to all the background

Image doesn' t look right, detail not sharp

Poor quality printing

Looks like xerox copy

Black, green, everything wrong

Printed wrong; darker, color heavier

Doesn’ t have right green

Terrible, print quality atrocious

Visual impression of bad, even before touching it, feel perhaps

Ok

Border too dark relative to light color - contrast not good

Has greenish cast

Something about script and face. Don' t like. Detail of little

Lines too particular

Brown color

Too dark, contrast wrong

Poor quality paper, doesn' t feel like linen

Lack of detail in border

Yellowish color

Feels funny

Off-color, not quite right

Paper feel wrong

Color wrong

Looks photocopied

Color wrong

Graphics wrong - mostly portrait fuzzy

4 2 7 5 B

Not sharp lines

Black is gray

Paper too stiff and smooth

Black ink wrong in color and intensity

Not familiar with 100’s. Not sure

Contrast of 100 over green seal wrong

Portrait hazy - not good resolution

Print doesn' t have texture

Line quality in borders (not good detail)

Some threads in paper, but bill looks wrong, not intaglio

Printing

12 less bold, central image mushy

Problems with federal reserve numbers-- vi bes wrong

Too smooth in feel

Feels funny

Little 100' s Paper feel

Lines faint, i ndi s t i nc t - - 1 ooks like photocopy

Paper feel smooth

I see very few 100' s

2-9
Stamped picture looks wrong

4 9 6 7 A Black is gray;

Paper different

Seal color washed out

Engraving not sharp

Black ink too faint - especially on portrait

Overall color wrong

Too clear (light) printing

White color is wrong

Portrait and "one hundred dollars" not printed well

Washed out looking, but has fibers

Tough; portrait wrong

Color wrong on seal

Quality of paper

Franklin looks different; expression and clothes look funny

Grayishness of black ink obvious

Poor image and border contrast catches attention

Feels funny

Looks washed out in color, with background particularly washed

Out

Printing too pale. Not enough contrast

Weak contrast

Portrait not good

Little 100’ s look funny

Paper feels funny

Printing is faint

Green tint overall

Counterfeiters must age them

Paper funny

Flatness of contrast in central image

Gray color of black ink

Paper doesn' t feel too good

Lathework, portrait good; feels like money but has few threads

Puzzled by Grant, but looks right anyway

Double bars over federal reserve bank number--must be ok

Reservations about 50’ s Ink looks funny

6 5 5 4 A

Paper wrong

Detail of engraving wrong

Yellow paper; everything

Paper flimsy

Ink too light

Color of paper wrong

Paper texture wrong

Print too light

Color

2-10
Sides (left and right) differ

Printing not sharp

Lathework wrong

Portrait looks wrong immediately

Print of letters worn off

Picture looks funny

Printing not precise

Portrait seems different

Portrait looks wrong, may lack detail

Ink funny

Background looks funny

Paper looks funny

Texture wrong

Lettering has wiped out in places, ink dissolved

Pi ct ure f aded

Not printed well--looks like offset

Color is wrong; graphics are ok

Printing quality off

Obvious counterfeit. Poor quality in central image -looks

washed out.

Guess it's OK; Looks different.

6786 A Paper feel wrong

Yellow

Seal too dark

Printing blotchy

Color of ink and paper wrong, not white enough

Feels too smooth

Color wrong

Too dark

Paper funny

Overall color too yellow

Paper too smooth

Printing quality not good; smeared, especially in green

Color all wrong - white is greenish

Looks like its been laundered - looks fuzzy

Paper quality wrong

Eyebrows wrong

D in federal reserve seal, and twenty on seal both crooked

Green wrong

Paper wrong

Portrait looks and feels flat

Dark print

Color of bill wrong; charcoal look wrong

Amateurish counterfeit. No contrast in central image. No

Definition

Yellowish aging of paper

Smudged greens

2-1
Speckling of border wrong

Secretary of treasury's signature wrong

Printing too dark. Too much contrast

Too dark. Contrast too strong

Lacks detail

Ink different - too clear (weak)

Paper looks funny

Yellow tint

Printing too dark (everywhere) Lettering not real sharp, numbers not clear

Green ink smudged on serial number

Dark areas too dark

Overall color wrong

7 3 6 8 A

Counterfeit; paper yellow

Different green serial #

Printing different

Paper too smooth

Ink not strong enough

Grain (texture) of paper too fine

No little threads

Paper hard

Paper appearance wrong

No threads present

Bad points on green seal

Feels papery; no fibers

Fi bers mi ssi ng

Central image quality wrong

Grayish blacks

Off-color green (yellowish)

Feels f unny

Not precise, especially portrait

Paper feels funny

100' s at bottom look wrong

Color of green in serial number and seal wrong, almost olive

Color is off

Seal is too uniform across the numbers

Portrait not sharp

Green really wrong

Portrait not bad but can' t feel intaglio

Paper feels funny

Some printing also not quite right

Feels like real bill

81 94A

Paper thin and fragile

Not sharply etched

Paper wrong, too thin

2-12
Paper is too light

Paper feels funny

Paper texture funny

Paper texture wrong

No fibers

Grant looks too stern

Poor quality printing

Portrait wrong paper

Green ink wrong

Lathework wrong

Poor quality paper - tears

Seems too thin for real age

Printing too dark

Too worn for $50

Paper feels funny

Paper too light

Paper feels funny

Green-gray has too much contrast

Portrait is not as sharp

Portrait engraving, poor highlights, poor border

Ink definitely smudged

Creases and folds wrong

91 1 1 B Yellow paper

Image wrong, bad in general

Paper feels wrong, weak, like newspaper

Color of black ink and of paper are wrong

Color wrong

General appearance

Paper quality wrong

Contrast wrong; too little gradation in shading

General appearance

Terrible. Lathework and portrait look like xerox

Terrible paper. Print comes off easily

Picture wears off--looks bad

Feels really funny

Yellow paper color

Darks too dark

Dark around border

Overall color wrong

Scroll details seem wrong on sides.

Paper texture wrong

Paper doesn' t have right feel, is falling apart - maybe bill

washed

Paper feel

Looks like photocopy

Portrait not right color

Hard to tell if wrong

Poor detail on green seal

Background color wrong, looks funny

was

2-1 3
Color is too yellow

Terrible quality of printing

Paper poor--has cardboardy feeling

Feels ironed; gut feeling that it’s bad

919 7C

Wear pattern wrong

Paper feel wrong

Engraving bad. Looks photocopied

Paper feels weak

Color is wrong, despite age

For a worn bill, the ten on seal is still quite even and not worn

Paper hard

Overall color wrong

Color wrong

Ink has bled into white background

No fibers

Needs date at bottom of seal

Washed out, especially portrait

Terrible. Black filled in

Green is yellowish

Poor detail

Paper poor quality

Quality of paper and print bad

Engraving quality poor

Hamilton is frowning

Extremely poor engraving; ink, printing wrong

Creases wrong

In such bad shape. Feels funny

Too dark around border

Not sure whose portrait is meant to be on the bill

Dark around borders

Paper feel wrong

Printing too dark

Overall tint is wrong

Face not clear

Very faded and worn

Ink different color and lightness

No reason to reject

9 2 3 5 A

Image contrast and clarity poor

General quality poor

Ink on paper too faint

Paper feels wrong

Overall color wrong

Print looks strange

Mottled areas ( smudges) --referred to it as ink

Paper texture wrong

Contrast in portrait wrong

2-14
Irregular points on green seal

No fibers

Triple chin on Franklin

Paper wrong

Printing wrong (particularly lathework and portrait)

Poor quality paper

Too much wear. Heavy enough but not enough detail

Print not good

Looks like a xerox

Black ink is grayish

Image quality of portrait poor, lack of crispness

Border poor

Losing some of its color with age

Needs better paper

Looks dirty. Not right

Ink washed out

Gray looking

Overall impression wrong, but nothing specific

Ink has faded; has been washed

Ink wiped away from picture - picture may also be wrong

Paper wrong

Fake dirt smudge

Too white. Light printing and background lacks color.

9 4 2 8 A

Paper wrong

Clarity, color wrong

Green numbers not sharp - not etched--pri nted other way

No threads

Paper feels funny

Discolored area--looks like dirt

Overall quality of engraving

Paper feels funny

Shouldn' t discolor in only one place

Paper wrong

Lathework dead, unclear

Green ink wrong

Portrait wrong

Vague feeling about engraving in center, lack of c ont r as t - - 1 l ke

looking at painting in the dark, no highlights

Printing too dark

Overall appearance wrong. Maybe contrast??

Ink color overall wrong

Feel of paper--slick

Horn; hard to tell

Printing under "For all debts" poor but may be BEP press defect

Did not look as detailed as it should

2-15
COMMENTS ABOUT GENUINE BILLS

0046 A Paper seems strange

Borders look funny

Paper feels funny

No fibers

100 and seal not aligned

Good copy - paper texture added - fake, doesn' t feel like

intaglio

Feels counterfeit; quality of the paper thin

Way paper has crinkled, more like cardboard

12' s vary, etc

Paper texture wrong

Too much detail in lines on border

Nothing striking

Wonder about check # (or plate #)

01 00A

Not enough fibers

Poor central image and background gradations, but could be good

Background seems a different color

Printing not sharp

No threads, but ok

Good blackness of ink. Paper feels right. Lathe a bit off

Feels, looks real

01 07A

Paper too smooth, lightweight

Paper funny

Bends, folds not as durable

Poor engraving - weak blacks

Little 100's strange

Looks real

Margins don' t seem to be even

Green color seems wrong (tint)

0 2 6 7 A Paper funny

Vertical lines across bill

Portrait quality

Alignment of seal

Poor contrast with central image

Weak blacks

Paper a bit smooth

2-16
Horn but real

Folds sharper

071 6B

Looks funny

Ink smeared at bottom (in twenty dollars)

Threads pulled out of bill

Unsure - paper too thick

Three defects in portrait background, also vest defect

Printing not sharp enough (stray ink)

Flexible bends good

Just realized scroll is correct

Overall tint

0 7 6 8 A

Printing defect in background of portrait

White area wrong

Printing around jacket looks irregular

Are Ortega and Regan on the same bill?

Paper a little thick

Paper texture wrong

Signature on left looks wrong

Misprinting in portrait background

Looks right, feels good

Noticed a color detail not previously noticed

New bill, threads, good paper

Better quality; print not worn down

0 9 3 4 A

Paper too hard

Franklin has broken nose, excellent counterfeit, otherwise

Looks too perfect. Suspicious of 100's

Not used to 100' s - counter 100 seems weird

Paper wrong

Good overall impression. (New is easier)

Looks real

1 1 3 9 B

Feels too smooth

Looks a little big, and margins unequal

Paper funny

No fibers

Paper feel wrong

Blunted points on seal

Too thin

Lack of highlights in central image

Looks funny; top 50' s so much larger than bottom ones

2-17
Federal reserve too small at top - perhaps should be usa

Paper feels bad

No threads

Not sharp

Portrait looks worn, but bill is worn, therefore ok

Portrait jumps out; paper feels better

Greenish cast to paper

1 2 2 7 A

Don' t like feel ( too papery! ) Impression of central image wrong - has poor highlights and

Contrast

Has threads. Looks good, not sure now

Looks and feels real

Not fuzzy; no misspellings; signature correct for age

.1 2 3 5 A

Green not sharp (white area) - not inked well

Paper texture wrong

Paper is strange

Paper too smooth

Discolored area that doesn' t seem like dirt

Excellent counterfeit, grayish blacks

Paper creasing

Lack of highlights in central image (flat)

Feel of paper wrong

100' s at bottom look odd

Paper wrong

Printing not right

Dirt smudges

Paper feels like paper, not like cloth

Threads present; portrait ok. Can’ t feel intaglio as well.

Franklin looks different

Funny feel

Feels thicker

Hashed out but ok

1278B

Stray printing again (ink where it doesn't belong)

Paper funny

Ink shows through from back

Counterfeit due to narrow borders. Gov' t should do better

Margin not even

Contrast too strong

Face looks splotchy? Maybe they all look like that

Feels funny

2-18
Also detail is not quite right

Color too whi t

Ink is too black

Generally looks for detail, misspellings, fibers, paper feel

Very good bill

1 3 7 2 A

Paper low quality

Hear pattern wrong; but image clear

Paper too thin; not strong enough; rips too easily

Portrait not clear

Uneven points on seal

No fibers

Generally good, but green is off

So is paper ( off)

Bad quality; very thin paper

Hamilton looks different

Obvious counterfeit; lack of gradation in background; lack of

Hi ghl i ght s Fold quality wrong - is too soft

Paper too thin

Paper wrong

Hamilton's lips look funny

Feels fine but detail of edge border seems larger

Feels di f f erent

Looks like it's been through the mill

1 6 9 5 A

Paper lightweight and flimsy

Crease of paper

Flat contrast of central image

Paper is thin, but looks ok

Horn, but looks good. No threads, tho. Green good

Better Hamilton; ok

1 741 D Green numbers bleed and federal reserve note printing blotched

Ink seems wrong color - too much black, too much contrast

Much of the detail is not good, printing not sharp, looks like bad

Photocopy

Seems washed out, lack of contrast with background

Different color--too white, too new

Too dark (printing)

Too dark on border areas

Printing not distinct, especially at top

Paper ok

Contrast too strong

Poor quality printing

2 - 19
Bleeding on top like a good one. Paper correct

Portrait intaglio. Lines a bit too thick--too much ink

Feels real

So different from previous bill (worn 20)

Graphics of portrait not as real

Black tint off

1 885 A Never noticed plate (?) numbers before (little ones)

Newer 50. Many threads. Paper, portrait good

Looks and feels real

Snappy colors and engraving

Like Grant better now

Have reservations about 50' s

1 941 D

Seems long

Excellent counterfeit. Weak green ink

Federal reserve heading, background fuzzy

Contrast too strong. Portrait too dark

Signature looks funny particularly 1 Paper not quite right

Printing not quite right

Some printing is smeared, especially Washington

Color off

Too much ink, but looks, feels real. Threads present.

1 942D

Not sharp; ink bleeding; signature bleeds

Paper feels wrong

Green didn' t print well on federal reserve note

Excellent counterfeit, like image, but doesn' t appear real

Color on words not uniform

Too much contrast in background vs. Border

Printing not clear

Feels like real thing but federal reserve note printing squished

Black ink bleeds, portrait feels like intaglio, threads present

2 1 1 9 A

Paper funny

Not enough contrast

Thought they were more green; shading, details good

expected more green on bill (unfamiliar with 100's),

Blacks not very dense. Printing varies

Paper feels right

Not f ami liar

Feels real (but all c-notes look funny). Green looks right

2-2 0
21 3 6 B Paper funny

Points blunted on black seal

Can see through counter numbers on seal

Beautiful counterfeit. Defect on cheek

Background too plain (white) and green seal too bright

Coloring funny, shading not exactly right, don' t see many IDO'

Mouth is wrong

Hard to tell; edges not sharp but paper is good

Paper too thin

Newer is easier, looks easier--all features and threads good

Feels, looks real

2 5 0 7 A

Dirty one; stiff, paper seems real; clear detail

Wouldn't accept myself; dirt covers too much

Wouldn't accept this bill; can't see seal, etc

Paper and stain funny

Dirt area--a real one wouldn' t circulate like that

Wrong pi cture?

Grant partially obscured; doesn’ t look right

Hard to see picture. Doesn' t look like him, but can' t see enough

to be sure

Dirt area bad

Green a different color, shows up bolder against dirt

Wouldn't take it but thinks its real, paper right

Don't like mutilation. All features, bleeding also

Graphics in center and border legends funny; wondered about 1's

Dirt caused problems

Too dirty to tell, especially portrait. Don' t want to decide

Dirty one - hard to tell

Printing not distinct

2679 A

Texture wrong

Uneven margins

Blunt points on seal

Not enough fibers

Hole s i n i

Background and overall image, focus on portrait and on 2-color

overpr i nt

Back of jackson's collar looks funny

Margin wrong

Numbers in corners look funny - too much contrast

Signature bothers

Bill itself is crooked, chopped off and misaligned

Hole in head

2-21
Green numbers too light - vary across bill, not raised enough

New--too smooth?

Feels good

Paper good

2792 A Paper wrong

Image not sharp; portrait poor

Paper funny

Problem with green seal points

Doesn' t seem like intaglio printing

Green color is perfect, but numbers not straight

Paper is wrong

Lack of central image highlights, blacks not dark enough

Noticed franklin's double chin

Hard to tell

Overall tint is a little wrong

Feels, looks real

Realized that small 100’s were right after all

Felt ok

2844 A Paper looks wrong

Paper feels too slick

Paper funny

Blunt points on green seal

Paper wrong < Folds too crisp

Cheap feel

100 and seal not aligned

Color for age not right

Good

Good paper quality, feel, gradation of graphics - all good

2 8 6 0 A

One flaw area in portrait

Paper funny

Poor rag quality

Obvious dark quality fibers

Defect in background image (not dirt)

Off-center both ways, but good contrast

Too good, too clean, too new

Margin is not even

Poor job printing green seal, not enough ink

Smudge on portrait background--is it printing or dirt?

A little light

Paper good. 100'S look different from others

Good print and paper

New ones seem different, somehow

2 - 22
2885 A Paper wrong

Image sharpness poor overall

Paper feels funny

Bad points on seal

No fibers, face OK

Crisp; would tear too easily

Too dark (printing)

Ok, but guessing; not good vibes, feels different

A little too black

Paper has long funny creases

Paper, green ink good

2 9 9 8B

Paper feel and quality poor

Too much discoloration and smudges

Paper dirty, hard to tell when old

No fibers

Paper is bad

Black is not black enough

Junction of coat and background, poor highlights and contrast

Looks like it' s been driven over by a truck

Border design seems wrong

Paper funny

Dingy background

Dirt makes it questionable

Looks like good, worn bill

3157A

Threads missing

Paper stiff

Seal bleedi ng

Blunted and uneven points on seal

100 and seal not aligned

Can’t feel intaglio. All 100's bad for that

Quality of paper poor

Dark color and wearing off. Print, features worn

Obvious. Lack of crispness in central image

Lack of crispness in federal reserve seal. Border engraving

better

Top 100 not same as bottom 100

3251 A

Waxy; paper quality poor

Paper too smooth, not substantial enough

Portrait not clear

Threads missing

Blunted points on both seals

2-2 3
No fibers

Paper worn badly. Is fuzzed

No threads

Looks real; but thin paper which would tear easily

Poor highlights in central image

Folded creasing

Slightly gray blacks

1* s in serial number just don' t look right, too square

100's different in background relative to face

More variability in dark oval area. Different from previous 100' s Feel of paper is a little wrong

3 2 6 7 C

Printing blotchy; green numbers not sharp

Ink smeared on Washington

Very dark relative to the other bills, but feels right

Excellent counterfeit. Top and bottom headings blurred and

spotted

Slightly washed out green

Contrast too strong. Spotty ink on bottom

Dots in areas not supposed to be printed. Printed lines not

always straight

Paper f unny

Paper feels funny

Too much ink; green ink is too light, but bill ok

Banner must be ok

Looks ok

3 2 9 7 A

Harder when old; paper yellowed

Paper too thin

Color hasn' t aged properly

Color completely wrong

Face; worn bills quality differs

Smeared image

Yellow color

Don' t like color ( green background color)

Too brown

Yellowed

Color is wrong; graphics are ok

A little dirty for 1977

Paper is worn

Dirty but looks good. Very soiled

No threads - harder to tell with old bills

Looks at patterni ng--di f f erent bills

Color strange; detail good

Yellow paper unusual

3 4 9 4 B

2-2 4
Not etched well; green numbers have hollow space, bleeding

General impression

Uneven points on green seal

Holes, good quality image

Too dark; too much contrast

Too much contrast; too strong

Paper feels wrong

Too many stray ink markings

Real, because black ink bleeds, threads present

Feels like the real thing; better quality paper

Looks ok

41 08B

Not etched well; printing of letters poor

Threads there but could be fake - too many

Paper feels like regular paper, not like $ bill

Some fibers, but feels wrong

Border a little too wide

Lines too well defined

Margin wrong

Too much contrast

Paper texture wrong

Clipped 5 in lower right is questionable

Trimming of edges is irregular

Paper and threads good. Portrait ok

Real

4 2 9 6 E

Paper not right; some thread there; wear pattern wrong

Portrait off; detail ok

No fibers

Bad points on seal

Lack of fiber

Irregular engraving on coat

Difference in quality of print. Features wearing easily

Very subtle central image problems, lack of crispness, highlights

Crease in center of paper seems wrong for real money

Paper good, intaglio, ink portrait good

Just noticed large edge borders

Secretary of Treasury was Miller??

Background too white

(Just realized who is supposed to be in the portrait)

431 7C

Threads missing

Background of portrait is too uniform

7' s asymmetric, not all the same boldness

Feeling paper harder to tell when worn

Texture slick, waxy, too smooth

2-2 5
Hamilton' s nose looks wrong

Outline of large ten in seal funny

Looks worn but genuine. Portrait still good, no threads--ok

Feels real; more durable

Looks real

4 7 2 3 A

Paper waxy; paper in general poor

Paper too slick

Paper feels wrong

Paper wrong

Overall coloring wrong

Not enough fibers

Paper feels funny

Paper wrong--worn fake

31ack ink is grayish

Central image lacks crispness

Uncertain due to extensive soil

Paper feel and printing feel

Can' t tell with 100' s Fibers not there

Franklin's name worn

Suspicious naturally of 100's

Green is smeared across white

Tinted strangely

4 8 6 9

*

Yellow paper

Paper feel wrong

Star? ? Has yellowed funny

Looks fake, has aged wrong

Color and grain (paper texture and threads) wrong

Fading is unusual color--yellowi sh

Overall color (yellowed)

Face looks different

Paper deliberately worn. No threads, too worn to tell, though

Would tear if folded too much

Paper folds funny

Peculiar color--so yellowish

Star after serial number looks out of place, unsure

Graphics ok; color wrong

Paper funny

Fiber not vi si ble--hard to tell since worn

Appears very dark as though drug through mud

Old and yellow; hard to tell

2-2 6
51 78B

Bad paper, funny feel

No f 1 bers

Ten not aligned with seal

Hay it'

printed - too heavy - but wouldn' t wear right

Central image lacks contrast in highlights

Sides seem wrong - not enough detail

Paper a bit smooth

Paper texture wrong

Lathework, portrait background good

531 1 A

Color of money wrong

Feel wrong

Margins very unequal

Paper feels funny

Margin off center

Overall printing is too light

Points on black seal wrong

Borders really off-center

Portrait is looking at me - seem funny

Lacks fibers

Trimmed unevenly

Poor ink definition. Poor contrast federal reserve seal

So far off-center in vertical direction

Don’ t like narrow border on top

Margin wrong

Border too light

Too much space at bottom, top cut off, not centered right

Green is good but bill is off center - something is wrong

It’s very light, though

Margin too far off center

531 8B

Color?* Overall impression wrong

Paper funny

Blunt and uneven points on black seal

Slightly different feel

Background washed out but border ok

Too light in border

Paper feel wrong

Printing too sharp and too much contrast

100 and seal not aligned

Looks good, but $100 bill looks wrong anyway--is too little

Head looks too big, but feels real

2-2 7
Ok

5 3 7 2 A Paper too slick

Different color where diagonal line is (upper left)

Doesn' t look so bad. Threads look black. Portrait good, but

lathework poor

Bill has been through the mill; tears easily

Low contrast of central image and border, gray ink

Margi n not even

Paper feels funny

Bill printed off-center; more space at top than bottom

5 6 5 4 A Paper too smooth for age

Paper funny

Grayi sh black

Creasi ng

Slight low contrast central image and heading banner

Lacks clarity in face

Feels wrong--too much body stiffness

Old, worn. Portrait background, lathework, green color good

harder to tell with old bills

OK

5 802 A

Totally confused; also face and suit he's wearing wrong

texture of fabric not convincing

Portrait wrong

Lathework wrong

Green numbers and seal wrong--too smooth

Imitated threads--too straight

Fold would tear easily

Very subtle. Moderately good highlights and contrasts in central

i mage

not as crisp as it should be, though

All 2' s not the same

Fiber sticking out

Tint is questionable

Darker stamp but looks real

5925 A Paper feels funny

Creasing wrong

Green numbers are too thin

Color wrong

Bill doesn't look like intaglio

Folds funny; real easy to tear

Paper folds funny

2-2 8
Faces start to look different

Fibers mi ssi ng

Numbers in corners don' t seem correct

Tint is a little off

Feels better

Feels ok

6092 A Impression of central image wrong

Printing defect in background

Some fibers

Lacks threads but good portrait

Scans bills for serial #' s the same, overall feel, color

lettering not fuzzy, misspellings, signatures correct,

6 1 0 1 B

Serial numbers not sharp

Lack of contrast central image

Green ink not very green

Contrast too strong - printing dark

Printing not right overall.

Jackson looks different

Borders of bill askew--too much white on one edge

Blurred Washington, d. C.

Trimmed unevenly

Seal area looks funny

Tint is wrong

Feels new, but doesn' t look right

Reservations about lack of white border at top

Too much black

Tint is wrong

Real but ink is too heavy

Printing much better

6 2 2 8 C

Ink in wrong places - dark spots, as if bad printing

Eyes; ink shows through from back

Uniform background

Stray dots - wonder if real

Well-used, but Hamilton looks good

Looks real

Like this one

6 2 9 5 E

Portrait and border not good gradation of black and grey

Colors too yellowed - looks fake - paper looks wrong

Paper feels wrong

Color wrong and missing threads

2-2 9
Overall c ol or -

- ye 1 1 o we

Paper texture wrong

Hard to tell with old bill

Points look worn through paper

Paper looks and feels wrong

No threads but good appearance

Central image, background detail poor

Usa banner poor

Paper creases

First 3 letters of signature too large, stand out

Paper thin

Printing too dark

Only color wrong - graphics ok

Worn

OK

6381 3

Doesn' t look right; overall impression wrong

Purple stamp; has threads; intaglio

paper good; green color a bit off, but ok

Mole on Grant' s face - never noticed before

Good

Grant looks better

6592B

Paper funny

Excellent counterfeit - but green is off-color

Blacks slightly gray

Portrait, lathework good

Green right color. Decision easier when bill not worn

Feels real

Are there supposed to be 50' s on the side and bottom?

There is no pattern between denomi nati ons

Color and paper ok

6 8 5 4 C

Blunt points on seal

More shading outer oval

Fold in middle looks funny

Serial it crooked and c' s look funny at end of it Good? Hard to tell

Color of paper a bit strange

Tint seems too greenish

Worn, some threads

Feels good

Small wrinkles compared with long defined wrinkles on bad ones

2-3 0
691 9B

Stray marks - looks like it's bad printing

Paper appearance wrong

No threads

No fibers

Grayish blacks

Margin uneven

Stray dots printed on bill

Feels more like real bill; portrait, lathework good

Felt ok

71 04B

Too hard paper

Feels papery

No fibers

Creased wrong

Wears badly

Funny black threads, but portrai t, feels like intaglio

Troubles with 50' s; worn in center

Smudging of ink, maybe dirt, close

50 in upper left larger than in upper right, upper set of #'

crooked and larger,

Paper thick, but wear is like good bill

Maybe thick paper?

Overall appearance?

71 44B

Paper feels funny

Something about face

Paper texture wrong

Unclear printing

Color of dark areas seems wrong

Threads, paper good but green a bit off

No clip on 5; good gradation of grays in background, vest of

portrait hits you

50' s in side legend don' t seem to belong

Darkness is strange--too new looking

Feels real

7 1 8 3 A

Green numbers aren' t well etched - lines not sharp enough,

numbers bleed

Paper too thin and stiff for age

Paper funny

Too much s hadi ng- - 1 ooks like dirt, but seems to be printing flaw

Bad points on green seal (twisting around)

Print too light; engraving not as clear as should be

2-31
Problems with Federal Reserve number

Feels too smooth

Overall appearance wrong

Noticed bottom border seemed unusual

Phoney due to 100' s on edges of bill

Getting confused with so many bills

Dirt smudged

Threads present; portrait ok

7234E

Yellow

Paper feel wrong; inking is ok

Feels like newspaper

Overall color poor

Hard to see fibers on this dirty bill

Portrait not quite right

No fibers

Paper--worn deliberately

Green numbers not straight and wrong color

Color is wrong. Too worn to tell

Feels ok; color wrong

Obvious counterfeit - crudeness of background

Color of paper wrong (old but aged too yellow)

No threads

Looks ok

7293*

Star?

Green numbers different. Fatter

Washington, d. C. Above seal isn' t aligned straight

Excellent counterfeit, grayish blacks

Paper creasi ng

Star after serial number doesn' t look right

Worn but real

Banner looks funny; guess it should be there

Old money causes problems in color and feel

7 3 3 3 B

Doesn' t look engraved; not uniform appearance

I ndi vi dual, features ok. Too much contrast overall (too white

background)

Threads there, portrait ok, but hard to tell

Feels ri ght

Stamped ok

Looks ok

7405 A

Not sure why; one flaw area

2-3 2
Paper feels hard

B1 unt poi nts

No fibers

Very good phoney. Ink not piled up

Black not so black, white lines not good in detail

Feels too stiff; not like money

Federal reserve printing different

New - more difficult when new

7 6 3 2 E

Good counterfeit. Federal reserve seal blurred. Portrait vague,

tho good

Paper feel

Signature for Secretary of Treasury looks wrong

Paper ok

Paper feel

Worn, but ok.

Feels more like real dollars

7701 A Paper too smooth

Paper funny

Not enough fibers

General appearance

No f i bers

Hashed out blacks

Looks light compared to previous bill (counterfeit)

No threads

Paper questionable

Different feel but ok

Seems real

7741 B

Hard to explain; not sure

Paper funny

Printing not quite clear enough

Paper feels funny

Are there supposed to be 50'on the side?

Bill in good condition

Good

7921 B

Portrait very distinct. Background doesn' t blend in as much - too outlined

Looks good but paper has dark fibers

Ok

Portrait jumps out. Paper feels better. Looks for greenish cast

to paper

2-3 3
Didn' t know money was so different for each denomination

The united states looks funny; not sure what 50 looks like

7 9 4 9 B Paper feel wrong

No threads

Not enough fibers

Quality of paper; old

Fairly decent counterfeit

Lack of highlights and gradation in central image and background

Paper wrong, but portrait good, etc

Looks washed or something

7 9 6 8 D Printing quality not good; Washington, D. C. especially bad

Washington, D. C. above seal is blurry

Good counterfeit. Blurring of border at top of federal reserve

note printing

Slightly grayish blacks

Breaks in underlining below image

Feels ok; but banner at top looks wrong

Jackson' s eyes; some other lines not clear

Looks very good

Stamped on correctly

Good

8081 A

Margins unequal

Face weird

Paper funny

Uneven borders

No fibers

Excellent counterfeit, hole in forehead

Vague feel

Lack of contrast - black has grayed

Don' t like narrow border

Uneven margin. Not centered

Irregular edge trimming

Margin off center

Out of alignment

OK

Green color good. No threads, but knows they can be sparse.

Lathework is good

Feels, looks good

8 3 5 0 A
Hear pattern on edges funny

Sharpness of engraving lacking - 11' s not clear

Paper texture wrong

Paper feels funny

Bad points on seal

Bad quality paper; torn edges

Feel of paper

No fibers

Horn, but feels right

Quality of central image and print is good

8361 A

Counterfeit - not sure why

Bad points on seal

Feels slightly funny

Smudged 5, good counterfeit

Contrast too strong

Hhite seems too bright

Hrong signature, treasurer is different

Lines of Hamilton's face and other lines seem wrong

Paper too smooth

Paper feels right

Purple numbers. Looks good

Paper better quality; looks good

8389F

All s not the same; triangle not printed sharply

Federal reserve not clear. Other lines are sharp

Texture wrong; paper too thick

Paper too hard

Uneven points on seal

USA banner poor

Poor detail on central image

Felt thi cker

Too light

Face is missing some lines; not sharp printing

Green through gray. Gray looks too deep, less transparent

usual

Jackson looks washed out

Feels good (paper) numbers, etc. Right. Green is a little off

Color darker in border and way stamped, feels real

8638C

Paper too light in feel, too thin

Color weird

No threads

Appears intentionally darkened

Fades with unusual yellow color

than

2-3 5
Color ( aged) - looks faked

Paper thin

Blunt points on black seal. Old ones difficult

Quality of paper wrong

Jackson's hand not in correct place (compared to other bills

Paper bad

Contrast (black) bad. Intaglio not there

Looks smaller

Federal reserve note printing squashed up

Hay paper has crinkled, feels softer and fuzzier

Dark printing

Paper aged

Paper feels funny

Dirty/old. Sepia color

Color looks wrong ( overall)

Looks ok

Seems awfully beat up, but still real

More concerned if bill is new - feel more sure with old ones

8 6 8 6 B Paper too light in feel

Colored fibers missing

Quality of paper poor. Houldn' t take many folds

Obvious. Central image poor

Creasi ng

Smudged, slightly gray blacks

Hamilton looks funny

Paper feels too light

Much used; portrait and lathework good despite age

Has been around a long time, but is ok

8731 A Paper too stiff for apparent age

Paper funny

No fibers

Doesn't usually carry 50's--USA printing looks funny

Portrait, lathework good. Green right color

Feels ok

Good

Reservations about 50'

in corners

8777A

Paper bad

Paper too smooth

Color too green overall

Paper funny

No fibers

Bad points on black seal

Paper doesn' t look right

2-3 6
Nose wrong; no mole on face ( had seen one on a bill he was sure

was good)

No fiber

Green good, but no threads

Paper wrong

Bad quality paper

Poor counterfeit, smudgy printing job

Gray image looks fuzzy

Lettering at top too small

Big 50' s funny

Overall color. Greenish tint

9052 A Prominent green parts - high contrast (seal and serial #)

Unsure about paper, no fibers

Folds are too crisp. Tears too easily

Creasing qualities of paper

Feels funny. Too rough

Crazy fifties, Federal Reserve note printing too small at top

Paper feels different; not same graininess (threads)

Paper a little light

Beat up, but paper feels good; lathework, portrait ok

9 1 3 9 B

Paper feels waxy

Appearance is ok; no threads

Looks worn, but paper is too stiff

Blunted points on both seals

Background engraving gradations, lack of highlights

Creasing wrong

Border too dark

Paper good, portrait good, but not quite right. Threads present

Feels real

Some have letters and #' s in bottom corners

9 1 5 9 A Portrait bad

Paper bad; wearing pattern different

Worn, printing not well aligned

Blunt poi nt s No fibers

Paper wrong

Blacks wrong

Doesn' t seem to be a quality note

Looks like it would tear; cheaper paper - not as durable

Poor paper quality

2-37
Border is too narrow

Expect new $100. Would question

Feels a bit f unny

9 2 6 5 A

Paper too lightweight

Poor quality paper. Weak at fold

Flat image quality. Gray ink

Old

Well used. Lathework, portrait good. Only see one thread

Reservations about 50' s in general

9602 A

I nk bleedi ng

Portrait looks fu 22 y--like photocopy

Paper wrong

Color of printed areas (all) wrong

Green ink smudges on white areas

Green dye faded into background and worn off in places

Don' t like his hair

Face--engravi ng not sharp

Smeared green ink. Has threads, though

Too papery; not durable enough

Poor quality of printing and background shading, ink is smudged

Paper seems too heavy for apparent age and degree of wear

Contrast is too weak

Green rubbed on to white area

Little 100' s in legend printed at bottom look wrong

Looks too old; hard to see printing

Feels a bit strange

Old bills hard. More normal white border

9695 A Color wrong

Border, black ink looks wrong.

Fiber coming out of paper

Right eye wrong, half closed

Cross-eyed grant

Fu 22 es, creases off

Purple numbers present. Paper wrong, mostly

Poor quality; tears easily

Poor ink definition - weak in contrast

Fold qualities not true

Feels like money

Border ok

Looks ok

9 8 8 2 B

2-3 8
Paper f unny

New, but paper doesn' t feel right

Unfamiliar with 50’ s Not enough fibers

Paper feel and printing too sharp

Uneven points on seal

Generally examine color and intensity of ink, feel for age

Intaglio feel. Threads present

Looks and feels real

Good, image quality crisp

2-3 9

APPENDIX

Table 3

- Decision Processes Reported by Participants During

Debriefing

Participant 1

Most noticeable is an overall impression of the sharpness of

lines

Feel of paper

Yellowed color

Line sharpness and quality are particularly variable across bill

Color of green seal

Portrait quality

Presence of threads

Numbers in central area

Participant 2

Most noticeable is the look and feel of the paper

Color is also important

Feel and color relative to apparent age are also important

Presence of threads may be helpful, but they are hard to see in

old bills; they are more obvious only in new bills

Participant 3

Look first at bill denomination in upper right-hand corner

Looks second at value of the bill printed over the seal;

here the contrast of the gray against the green is most

i mportant

Looks third at the portrait and wear pattern. These should be

even despite age. Portrait-background contrast should be sharp

and any fading should be uniform

Tried looking at engraving in border but didn’ t find it very

useful

Found the most trouble occurred with creased and worn bills

Participant 4

Began by looking at detail carefully

Later looked at shading and contrast and

felt real bills have most gradation

Looked for threads

Found older bills harder

Paper should have semi-rough texture

Participant 5 Looked for blunt points on seals and lack of fibers

Color often not white enough with blacks not black enough or fine

enough

Jackson frequently looked fake, with closed eyes

3-1
Table 3 - (Continued)

A real bill should be grayish because of fine lines

Dirt causes color problems, while washing bills causes problems

with fading

Noticed much variability in portraits with some lacking a great

deal of detail. This was particularly true of Jackson

Parti ci pant 6

Looked first at overall printing quality, where defects were

some times quite obvious

Looked for colored threads, but had trouble finding them in worn

bills

On a worn bill, looked at engraving, especially the details of

the portrait

On a new bill, easier to look at quality and find fibers

Found much smeared ink, particularly "Washington, D. C. " above

seal

Treasury seal should be aligned with denomination - easy to spot, but not most important

Trimming of bills is worse on new ones

Noticed more details as experiment progressed

Par t i c i pant 7

Black printing and lathework should be clean and heavy

Portrait should also be clear

Paper should feel right, with feel being a good diagnostic tool

Hue and type face of green printing also important

Participant 8

Most important - focus on portrait crispness vs. fuzziness

Central image (portrait) should have subtlety and sharpness in

contrast

Became more critical of color and density of black and green inks

Looked at thin lines at top and bottom of bill

Aged color appearance was a strong factor in older counterfeits

Creasing was also a strong factor, although less so with new

bills

Density of blacks also important

Background engraving important along with white holes around

portrait

Participant 9

Examined portrait first

Found general color and overall contrast important

Margin size important - varied frequently

Not always easy to tell, but the easiest cue was

that printing was too dark or too light in color

3-2
Table 3 - (Continued)

Parti ci pant 1

General color of paper important - odd if very yellowed

Variations in detail of border very easy to detect (50'

in $50

bills)

Feel of paper - should not be slick, coarse, or grainy

Looked more at borders, and treasury seal

Would have passed much of the currency in a real situation

Parti ci pant 1

Feel important

Serial numbers should be the same and lettering should be uniform

Edges should be uniform - some were way off

Color of green ink often blurry, but not the same as when washed

Checked for accuracy of signature ( e. g. Regan on '81 bills)

Fuzziness is a positive quality - money usually stands up well

Texture and color, fading and shading are most important

Noticed a $10 with wrong writing

A lot didn' t have enough green; color appeared wrong due to dirt,

perhaps an illusion. Very hard to determine with older bills

Parti ci pant 1

Feel important

Overall appearance of printing quality, especially contrast - noticed if too heavy rather than delicate

Some bills were aged too much - as if intentional

Rough areas occurred - looked for stray in counter zeroes

and lack of sharpness

Bills often not centered on paper - an easy cue,

but may not be useful

An aged bill should all blend together - should not appear intentionally aged

Par t i c i pant 1

Color of printed border and other designs examined first

Looked at background contrast along with trim - often obvious

General appearance important - if graphics wrong, obvious

count erf ei

Overall color made it hard to tell, especially if worn and aged

Thickness of paper varied and made decision difficult

paper tends to fluff when aged

Gradually became less skeptical of new bills being too thin

Participant 14

Color variations easiest to detect

Threads were missing on too many bills

Much variation in texture and feel of paper

Year and wear should go together with color vs texture bein*?

compatible ( e. g. bill should be soft if old and worn appearing

Always looked at portraits

3-3
Table 3 - (Continued)

Noticed that ink on printing smeared sometimes

Participant 15

Hard texture of paper and engraving of border

Overall lightness and darkness of printing

Apparent age and wear for year printing

Printing quality was hard to tell in general

During the experiment, changed perception of texture,

and noticed more engraving

Participant 16

Overall appearance and color most important

Feel of paper important

Noticed any unusual printing, discolored areas, and inconsistenci es

Serial numbers were sometimes too yellow

Rarely looked at line quality or portrait

Parti ci pant 1

Quality of paper in bends and folds, as well as easiness of

ri ppi ng

Quality of engraving and overall legibility

Thin feel, more like paper than like money

"Federal Reserve note" engraving varied with bills - sometimes

too narrow

Color of printing, as well as darkness and heaviness of ink

Ink sometimes wearing off

Features of both Franklin and Grant seemed to vary

Paid more attention to printing quality and less to actual

wri ti ng

Parti ci pant 1

Clarity of background and face detail important

Centering of bill and margins varied

Overall color and shading varied

Noticed nature of paper (run fingers over bill to tell)

Noticed contrast and clarity of detail as a function of age

Became more familiar with bills, noticed darker outer borders

Par t i ci pant 1

Noticed feel, color

Detail of printing - some bills were too detailed

Some margins were too narrow

Contrast of printing on paper was often too much or too little

Hear wrong - bill was too beat up for date

Portraits often didn' t look right - faces seemed to differ

( but unfamiliar with $50' s and $100’ s)

Noticed uneven borders right away

Background color way off - white wrong

3-4
Table 3 - (Continued)

Participant 20

Mostly overall color and contrast

Paper feel

Seemed to get harder - became less sure of what real bills should look like

Medium wear bills looked best

Part i ci pant 21

Paper texture important for most bills

Clarity of print quality

Unusual coloring and aging

Looked at bill overall rather than at specific features

Checked portrait for accuracy

Became more tolerant of differences in printing quality during

experiment

3-5

APPENDIX

Table 4. Measured CIE Chromaticity Coordinates and Luminances for

Counterfeit Bills Used in Pilot Study

Denom RP# Serial# Descrip x y u V Lum

$20 103 6786A lathe frt .4636 .4239 .2590 .3552 22.0

$20 103 6786A white .4749 .4304 .2633 .3579 106.

$20 103 6786A green .3867 .4902 .1908 .3627 23.9

$20 103 6786A portrait .4618 .4217 .2588 .3545 21.2

$20 103 6786A blk letter .4603 .4180 .2594 .3535 13.8

$20 104 0759* lathe frt .4631 .4236 .2588 .3551 34.0

$20 104 0759* white .4746 .4278 .2642 .3573 81.5

$20 104 0759* green .4015 .4805 .2017 .3621 40.1

$20 104 0759* portrait .4627 .4231 .2588 .3550 29.5

$20 104 0759* blk letter .4568 .4199 .2564 .3536 16.4

$50 15 2236D lathe frt .4631 .4206 .2601 .3544 18.2

$50 15 2236D white .4657 .4267 .2591 .3561 121

$50 15 2236D green .4313 .4727 .2209 .3632 58.3

$50 15 2236D portrait .4647 .4216 .2607 .3548 39.2

$50 15 2236D blk letter .4672 .4181 .2638 .3542 13.4

$50 18' 1381A lathe frt .4746 .4225 .2666 .3560 19.9

$50 18 1381A white .4869 .4256 .2730 .3580 92.9

$50 18 1381A green .4558 .4617 .2390 .3631 54.8

$50 18 1381A portrait .4797 .4236 .2694 .3568 36.2

$50 18 1381A blk letter .4786 .4192 .2706 .3556 12.7

$20 25 9111B lathe frt .4712 .4236 .2640 .3559 22.8

$20 25 9111B white .4846 .4276 .2707 .3582 86.1

$20 25 9111B green .4465 .4646 .2325 .3629 43.4

$20 25 9111B portrait .4749 .4234 .2664 .3562 21.7

$20 25 9111B blk letter .4673 .4214 .2625 .3550 15.6

$20 27 4051D lathe frt .4710 .4237 .2638 .3559 16.1

$20 27 4051D white .4805 .4287 .2676 .3581 107.

$20 27 4051D green .4316 .4779 .2194 .3643 42.0

$20 27 4051D portrait .4710 .4236 .2638 .3559 21.1

$20 27 4051D blk letter .4721 .4199 .2661 .3551 14.3

$50 44 3691H lathe frt .4527 .4227 .2527 .3539 31.4

$50 44 3691H white .4635 .4271 .2576 .3560 142 . $50 44 3691H green .3784 .4908 .1861 .3621 59.2

$50 44 36 91H portrait .4583 .4244 .2555 .3548 54.8

$50 44 3691H blk letter .4613 .4184 .2600 .3537 14.6

$50 45 0395D lathe frt .4579 .4243 .2553 .3548 31.8

$50 45 0395D white .4692 .4265 .2614 .3564 118.

$50 45 0395D green .3971 .4754 .2008 .3606 44.0

$50 45 0395D portrait .4611 .4228 .2579 .3547 42.5

$50 45 0395D blk letter .4603 .4213 .2581 .3543 21.6

$20 48 3271C lathe frt .4737 .4268 .2641 .3569 28.7

$20 48 3271C white .4913 .4299 .2738 .3594 81.0

$20 48 3271C green .4441 .4628 .2317 .3622 50.2

$20 48 3271C portrait .4788 .4258 .2678 .3572 22.0

$20 48 3271C blk letter .4711 .4246 .2634 .3562 18.9

$50 90 8194A lathe frt .4548 .4207 .2548 .3536 31.3

$50 90' 8194A white .4672 .4278 .2595 .3565 124.

$50 90 8194A green .3825 .4887 .1889 .3620 29.1

$50 90- 8194A portrait .4572 .4219 .2558 .3543 5 4.5

$50 90‘ 8194A blk letter .4602 .4182 .2594 .3535 23.9

4-1
Table 4 - Continued

Denom RP# Serial# Descrip X y u V Lum

$10 63 0324E frt lathe .4711 .4242 .2636 .3561 32.9

$10 63 0324E white .4728 .4301 .2621 .3577 125.

$10 63 0324E green .4106 .4762 .2081 .3620 48.3

$10 63 0324E portrait .4686 .4235 .2624 .3556 22.1

$10 63 0324E blk letter .4722 .4220 .2653 .3556 24.0

$10 60 0436D frt lathe .4733 .4268 .2639 .3569 20.4

$10 60 0436D white .4835 .4306 .2686 .3588 85.2

$10 60 0436D green .4376 .4803 .2219 .3653 39.4

$10 60 0436D portrait .4752 .4254 .2657 .3567 20.1

$10 60 0436D blk letter -.4693 .4234 .2628 .3557 16.4

$100 70 1292A frt lathe .4658 .4267 .2592 .3561 49.6

$100 70 1292A white .4693 .4293 .2603 .3571 95.3

$100 70 1292A green .3801 .4984 .1850 .3638 37.7

$100 70 1292A portrait .4639 .4252 .2587 .3556 38.7

$100 70 1292A blk letter .4606 .4198 .2589 .3539 19.1

$10 64 3652F blk letter .4584 .4253 .2551 .3551 21.1

$10 64 3752F frt lathe .4598 .4256 .2559 .3553 36.0

$10 64 3752F white .4656 .4283 .2584 .3565 111.

$10 64 3752F green .4029 .4830 .2017 .3627 48.7

$10 64 3752F portrait .4581 .4267 .2544 .3554 31.2

$100 5

‘ 3807A lathe frt .4580 .4238 .2555 .3547 32.0

$100 5 3807A white .4666 .4280 .2591 .3565 113.

$100 5 3807A green .3611 .4987 .1748 .3622 33.3

$100 5 3807A portrait .4579 .4240 .2554 .3547 38.7

$100 5 3807A blk letter .4481 .4173 .2520 .3521 10.4

$100 4 4275B lathe frt .4612 .4242 .2574 .3551 59.0

$100 4 4275B white .4627 .4276 .2569 .3560 134.

$100 4 4275B green .3855 .4861 .1912 .3618 47.6

$100 4 4275B portrait .4577 .4232 .2556 .3545 44.8

$100 4 4275B blk letter .4639 .4184 .2616 .3539 21.6

$100 9 4967A lathe frt .4594 .4275 .2548 .3557 49.5

$100 9 4967A white .4680 .4294 .2594 .3570 117.

$100 9 4967A green .4132 .4667 .2126 .3602 34.2

$100 9 4967A portrait .4598 .4267 .2554 .3555 51.6

$100 9 4967A blk letter .4547 .4234 .2536 .3542 30.1

$100 68 6554A lathe frt .4617 .4265 .2567 .3557 37.1

$100 68 6554A white .4727 .4293 .2624 .3574 121.

$100 68 6554A green .3860 .4934 .1895 .3633 41.7

$100 68 6554A portrait .4599 .4267 .2555 .3556 39.7

$100 68 6554A blk letter .4637 .4225 .2597 .3549 21.3

$100 10 7868A lathe frt .4625 .4218 .2592 .3546 38.1

$100 10 7868A white .4717 .4265 .2629 .3567 125.

$100 10 7868A green .4366 .4634 .2272 .3617 50.6

$100 10 7868A bl & white - - - - - $100 10 7 86 8A portrait .4610 .4225 .2580 .3546 41.2

$10 34 9197C frt lathe .4692 .4244 .2624 .3559 26.7

$10 34 9197C white .4876 .4276 .2726 .3585 79.3

$10 34 9197C green .4497 .4606 .2358 .3623 34.7

$10 34 9197C portrait .4749 .4243 .2660 .3565 20.6

4-2
Table 4 - Continued

Denom RP# Serial# Descrip X y u V Lum

$10 34 9197C blk letter .4685 .4215 .2632 .3551 10.6

$100 72 9235A frt lathe .4625 .4204 .2583 .3552 48.7

$100 72 9235A white .4635 .4276 .2573 .3561 122.

$100 72 9235A green .4160 .4649 .2148 .3601 50.9

$100 72 9235A portrait .4666 .4240 .2609 .3556 42.3

$100 72 9235A blk letter .4634 .4221 .2597 .3548 29.3

4-3

APPENDIX

TABLE 5.

Denom Serial# Cond Sp Descrip X y Err u V Va lue

100 D01705318B 1 3 white .4638 .4286 6 .2571 .3564 8.31

100 G141821 19A 1 3 white .4660 .4295 3 .2581 .3568 8.22

100 E01764108B 1 3 white .4648 .4283 6 .2579 .3564 8.39

100 G03085925A 2 3 white .4636 .4296 4 .2566 .3566 8.17

100 B02553157A 2 3 white .4701 .4297 7 .2606 .3573 7.81

100 B32912844A 2 3 white .4640 .4304 5 .2565 .3568 7.84

100 B05499602A 3 3 white .4683 .4279 13 .2602 .3567 7.49

100 E14559159A 3 3 white .4681 .4306 8 .2589 .3573 7.62

100 A14123251A 3 3 white .4707 .4305 8 .2606 .3575 7.52

50 E10917 144B 1 3 white .4668 .4290 4 .2588 .3568 8.34

50 B37 141855A 1 3 white .4662 .4295 1 .2582 .3568 8.45

50 B25685311A 2 3 white .4679 .4300 12 .2591 .3571 7 .82

50 K05244980A 2 3 white .4683 .4296 2 .2595 .3571 8.03

50 E05537104B 2 3 white .4704 .4290 6 .2611 .3571 7.59

50 E12599052A 2 3 white .4668 .4288 6 .2589 .3567 8.31

50 A08672507A 3 3 white .4692 .4277 11 .2609 .3567 8.25

50 C00978776A 3 3 white .4683 .4303 10 .2592 .3572 7.24

50 C07989265A 3 3 white .4690 .4296 3 .2599 .3571 7.63

20 L37461741D 1 3 white .4616 .4285 8 .2558 .3562 8.27

20 E79296101B 1 3 white .4651 .4287 4 .2579 .3565 8.19

20 E43377968D 1 3 white .4646 .4292 5 .2574 .3566 8.28

20 G91986092A 2 3 white .4695 .4307 1 .2598 .3575 8.13

20 B33996919B 2 3 white .4664 .4298 5 .2582 .3569 7.98

20 B12726295E 3 3 white .4801 .4303 11 .2666 .3584 7.44

20 B40192998B 3 3 white .4867 .4267 6 .2724 .3582 6.35

20 B13224869* 3 3 white .4883 .4301 12 .2719 .3592 6.71

10 E04378361A 1 3 white .4660 .4289 7 .2584 .3567 8.26

10 A06357333B 1 3 white .4659 .4297 1 .2580 .3569 8.17

10 B33714296E 2 3 white .4680 .4297 5 .2593 .3571 7.89

10 B82477632E 2 3 white .4637 .4298 1 .2565 .3567 7.88

10 G15914317C 3 3 white .4711 .4290 2 .2615 .3572 7.68

10 J14141372A 3 3 white .4704 .4304 9 .2605 .3575 7.92

5-1
Table 5 - (Continued)

Denom Serial# Cond Sp Descrip x y Err u V Value

100 D01705318B 1 4 green. seal .3454 .5190 6 .1618 .3648 5.11

100 G14182119A 1 4 green .seal .3318 .5341 3 .1518 .3664 4.17

100 E01764108B 1 4 green. seal .3269 .5374 6 .1487 .3666 4.74

100 G03085925A 2 4 green. seal .3521 .5138 4 .1664 .3643 4.84

100 B02553157A 2 4 green. seal .3551 .5072 7 .1696 .3633 4.63

100 B32912844A 2 4 green .seal .3771 .4970 5 .1837 .3632 4.98

100 B05499602A 3 4 green. seal .4049 .4742 13 .2055 .3610 4.48

100 E14559159A 3 4 green. seal .3432 .5272 8 .1589 .3661 4.14

100 A14123251A 3 4 green. seal .4806 .4713 8 .2498 .3675 5.29

50 E10917144B 1 4 green. seal .3675 .4984 4 .1783 .3627 5.34

50 B37141855A 1 4 green. seal .3561 .5111 1 .1691 .3642 4.87

50 B25685311A 2 4 green .seal .3879 .4905 12 .1913 .3629 5.22

50 K05244980A 2 4 green .seal .3758 .4979 2 .1828 .3633 4.85

50 E05537104B 2 4 green .seal .3712 .5007 6 .1796 .3634 4.72

50 E12599052A 2 4 green .seal .3358 .5426 6 .1520 .3683 3.97

50 A08672507A 3 4 green . seal .3612 .5048 11 .1733 .3634 3.85

50 C00978776A 3 4 green. seal .3820 .4909 10 .1880 .3624 4.74

50 C07989265A 3 4 green . seal .3872 .4890 3 .1914 .3625 5.18

20 L37461741D 1 4 green .seal .3731 .4945 8 .1823 .3624 5.40

20 E79296101B 1 4 green. seal .3579 .5091 4 .1706 .3639 4.92

20 E43377968D 1 4 green .seal .3627 .5013 5 .1750 .3628 5.21

20 G91986092A 2 4 green . seal .3759 .5028 1 .1816 .3643 5.20

20 B33996919B 2 4 green .seal .3647 .5105 5 .1737 .3648 5.00

20 B12726295E 3 4 green . seal .3982 .4870 11 .1979 .3631 4.54

20 B40192998B 3 4 green . seal .3933 .4914 6 .1940 .3635 4.47

20 B13224869* 3 4 green. seal .4102 .4789 12 .2070 .3625 4.82

10 E04378361A 1 4 green . sea 1 .3434 .5110 7 .1626 .3630 4.88

10 A06357333B 1 4 green .seal .3586 .5082 1 .1711 .3638 4.96

10 B33714296E 2 4 green. seal .3404 .5225 5 .1585 .3650 4.27

10 B82477632E 2 4 green. seal .3514 .5139 1 .1661 .3643 4.48

10 G15914317C 3 4 green . seal .3956 .4828 2 .1977 .3620 5.27

10 J14141372A 3 4 green .seal .3683 .5090 9 .1760 .3648 4.59

5-2
Table 5 - (Continued)

Denom Serial# Cond Spot Descrip x y Err u V Va lue

100 D01705318B 1 8 black. letter .4633 .4186 6 .2611 .3539 2.51

100 G14182119A 1 8 black. letter .4615 .4166 3 .2609 .3532 2.21

100 E01764108B 1 8 black. letter .4629 .4168 6 .2617 .3534 2.40

100 G03085925A 2 8 black. letter .4571 .4207 4 .2563 .3538 2.29

100 B02553157A 2 8 black. letter .4605 .4229 7 .2575 .3547 2.98

100 B32912844A 2 8 black. letter .4571 .4216 5 .2559 .3540 2.66

100 B05499602A 3 8 black. letter .4548 .4272 13 .2521 .3552 3.84

100 E14559159A 3 8 black. letter .4573 .4234 8 .2553 .3545 3 .03

100 A14123251A 3 8 black. letter .4584 .4253 8 .2551 .3551 3.39

50 E10917144B 1 8 black. letter .4638 .4191 4 .2612 .3541 3.20

50 B37141855A 1 8 black. letter .4618 .4219 1 .2587 .3546 3.21

50 B2568531 1A 2 8 black. letter .4561 .4271 12 .2529 .3553 3.68

50 K05244980A 2 8 black. letter .4607 .4209 2 .2585 .3542 2.89

50 E05537104B 2 8 black. letter .4587 .4210 6 .2572 .3540 2.46

50 E12599052A 2 8 black. letter .4597 .4224 6 .2572 .3545 2.89

50 A08672507A 3 8 black. letter .4612 .4209 11 .2588 .3543 2.66

50 C00978776A 3 8 black. letter .4572 .4220 10 .2558 .3541 2.72

50 C07989265A 3 8 black. letter .4578 .4240 3 .2553 .3547 2.93

20 L37461741D 1 8 black. letter .4654 .4175 8 .2630 .3539 2.75

20 E7 9296101

1 8 black. letter .4615 .4214 4 .2588 .3544 2.90

20 E43377968D 1 8 black. letter .4649 .4163 5 .2632 .3535 2.51

20 G91986092A 2 8 black. letter .4584 .4223 1 .2564 .3543 3.16

20 B33996919B 2 8 black. letter .4568 .4245 5 .2545 .3547 3.61

20 B12726295E 3 8 black. letter .4673 .4258 11 .2605 .3561 3.52

20 B40192998B 3 8 black. letter .4639 .4223 6 .2599 .3549 2.98

20 B13224869* 3 8 black. letter .4632 .4255 12 .2581 .3556 3.13

10 E04378361A 1 8 black. letter .4613 .4206 7 .2590 .3542 2.83

10 A06357333B 1 8 black. letter .4595 .4183 1 .2589 .3535 2.88

10 B33714296E 2 8 black. letter .4611 .4223 5 .2581 .3546 3.02

10 B82477632E 2 8 black. letter .4581 .4222 1 .2563 .3543 2.82

10 G15914317C 3 8 black. letter .4559 .4239 2 .2542 .3545 3.30

10 J14141372A 3 8 black. letter .4559 .4251 9 .2537 .3548 3.14

5-3

NBS-114A i rev. 2-80

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 85-3160

2. Performing Organ. Report No. 3. Publication Date

JULY 1985

4. TITLE AND SUBTITLE

Noticeability of Features of Secure Documents

5. AUTHOR(S)

Belinda L. Collins, Suzin Mayerson and James A. Worthey

6. PERFORMING ORGANIZATION (If joint or other than NBS. see in struction s)

national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

Bureau of Engraving and Printing

U.S. Treasury Department

Washington, D.C.

10.

SUPPLEMENTARY NOTES

| | Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. I f document includes a significant

bibliography or literature survey, mention it here)

A review of the literature on the noticeability of features of counterfeit bills,

primarily British pound notes, is presented. The review points out the importance o^

prolonging the attention paid to a bank note as a counterfeit deterrent. Various desig..

options are suggested. A pilot study on the noticeability of features of counterfeit.

US dollars is also presented. The study includes both spectroradiometeric measures ol

the chromaticity and luminance of a set of counterfeit bills and an identification stud\

In the identification study, 21 participants selected counterfeit bills from a much

larger stack of genuine bills. They also listed the features they notices as the. made

their selection. Each participant successfully identified about 80 percent of the

counterfeit bills, although only one counterfeit was identified by all participants.

Features noticed included problems with the portrait appearance, lack of detail, color

(both of the paper and the green seal), contrast, and feel. Participants also made

many errors with genuine bills, although they noted fewer features and often mentioned

printing press defects.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate <ey wore-. . attention; chromaticity; counterfeit bills, counterfeit deterrent; ident if icat n; luminance; spectroradiometric measures

13.

AVAILABILITY

| 1 Unlimited

fX| For Official Distribution. Do Not Release to NTIS

| 1 Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

| I Order From National Technical Information Service (NTIS), Springfield. VA. 22161

14. NO. OF

PRINTED PAGE

15. Pr