U. S. DEPARTMENT OF COMMERCE

DANIEL C. ROPER, Secretary NATIONAL BUREAU OF STANDARDS

LYMAN J. BRIGGS, Director

NATIONAL BUREAU OF STANDARDS MISCELLANEOUS PUBLICATION M149

A BASIS FOR A PERFORMANCE SPECIFICATION

FOR WOMEN'S FULL-FASHIONED

SILK HOSIERY

By

Herbert F. Schiefer and Richard S. Cleveland

Issued April 25, 1935

UNITED STATES

GOVERNMENT PRINTING OFFICE

WASHINGTON ; 1935

For sale by the Superintendent of Documents, Washington, D. C, Price 5 cents

A BASIS FOR A PERFORMANCE SPECIFICATION FOR

WOMEN'S FULL-FASHIONED SILK HOSIERY

By Herbert F. Schiefer and Richard S. Cleveland

ABSTRACT

The results of a survey on women's full-fashioned silk hosiery purchased from

fourteen retail stores located in eight large cities in different parts of the United

States are discussed. The brand, retail price, appearance, and construction are found to be inadequate guides to the performance of the stockings as indicated by

tests on the National Bureau of Standards hosiery-testing machine, which measures the physical characteristics of the upper part of the leg of the stockings

under repeated stretching.

Minimum limits for "distensibility", "recoverability and "stretch-endurability" of the stocking; a classification of hosiery based upon the thickness of two

layers of the leg fabric of the stocking; tolerances for size and length of the stocking; and a requirement for color fastness to laundering are recommended for use

in a performance specification for women's full-fashioned silk hosiery.

CONTENTS

Page

I. Introduction 1

II. Samples 2

III. Test procedure 4

IV. Test results 4

1. Size .... 4

2. Length 5

3. Classification, thickness, and weight. 6

4. Machine tests 8

(a) Distensibility 9

(b) Recoverability 9

(c) Stretch-endurability 12

5. Color fastness to laundering 12

V. Miscellaneous 13

1. Check tests _ 13

2. Dimensions of parts 14

3. Other tests _ 14

VI. Summary.- 14

I. INTRODUCTION

An instrument for measuring the elastic properties of hosiery has

recently been developed.1 The performance of the instrument has

been investigated by testing hosiery of known history.2 This work

indicated that the instrument is capable of measuring certain properties of hosiery which have heretofore been studied, if at all, only

through the laborious and expensive process of service trials. It would seem that these properties are of direct interest to both the consumer and manufacturer, particularly the former. With a meth-

^erbert F. Schiefer and William D. Appel, Hosiery4esting machine. BS J. Research 12, 543 (1934) RP679.

s Herbert F. Shiefer and Richard 8. Cleveland, Factors affecting the performance of hosiery on the hosierytesting machine. J. Research NBS 14, 1 (1935) RP753.

122287—35 1 1
2 Miscellaneous Publications, National Bureau oj Standards

od for measuring them at hand, it seemed logical to apply this method

to samples of hosiery selected, so as to give a representative cross section of the present market. The results of these tests should give a clear picture of the present qualities being offered, and indicate the

directions along which improvement can be made.

The purchasers of hosiery at the retail counter must be guided by

the following items: Size (length of foot)—can be had as specified.

Length—unless the customer specifies otherwise, she may expect

to get a stocking of the standard length of 30 ±1 inch.3 Appearance—she will expect to make her own selection as to color and

texture, and may be given information as to the fastness of the dye.

Weight—the hosiery will be advertised as

1 'chiffon", "service", or some similar term. These terms are used rather loosely to indicate

weight and appearance. A chiffon stocking is lighter in weight than

a service stocking, and is therefore considered to have a more pleasing

appearance.

Manufacturers and retailers have a more precise system of terminology, which sometimes reaches the consumer through advertising.

Thus, a fine-textured chiffon stocking might be called a "3-thread,

51 -gage." This expression is intended to specify the size of the yarn

and the closeness of the knitting, but unfortunately these terms are not perfectly definite. The expression " 3-thread" means that the

silk yarn is composed of 3 threads of silk twisted together. A thread,

as used in the hosiery industry, generally contains 8 to 14 silk fila- ments, and varies in average size from 13 to 15 deniers. In twisting

together 3 such threads to make a yarn, there is the possibility of

having these variations additive. Moreover, the diameter of the

yarn is somewhat dependent upon the twist. The covering power

of the yam, and therefore the appearance of the stocking, may vary

with this factor. The expression "51-gage" means that there are

51 needles in 1.5 inch of the needle bar, each needle producing a stitch or wale in the fabric. If the full width, 14 inches, of the needle bar were used in knitting the stocking, there would be 476 wales in the

widest part of the fabric, which is above the first fashion marks.

However, the fabric is extensible and may be set, by certain fin- ishing processes, in either a stretched or shrunken condition. The

number of wales per 1.5 inch in the finished stocking does not necessarily indicate that the same number of needles per 1.5 inch in the

needle bar were used in knitting it. Since the term "gage" is applied

indiscriminately to the fabric and to the machine, its meaning is somewhat indefinite.

II. SAMPLES

With the assistance of the National Ketail Dry Goods Association,

eleven stores were selected, in eight widely separated cities. Two

mail-order houses and one large chain store were added to the list. The most popular, the cheapest, and usually the most-expensive style

numbers were purchased from all stores. From some, all of the style

numbers of a given brand were purchased; whereas corresponding

style numbers of well-known brands were purchased from several

stores located in the same or different cities. Of one brand, 13 style

numbers were purchased. Altogether, 32 brands were represented,

of which at least 15 are nationally advertised. There were 111 sam3 Hosiery Lengths. BS Commercial Standard CS46-33 (1933).
Schiefer 1 Cleveland] Basis for Women 's Hosiery Specification 3

pies, each sample consisting of two pairs of stockings. The information given us by the stores when the purchases were made is shown

in table 1. Table 1.

Description of samples

$0.59

.59

.59

.69

.79

.79

.79

.79 .79

.79 .79 .79

.79

.79

.85

.85

.85

.85 .85

.95

.95

.95

.95

.95

.95 1.00

1.00 1.00

1.00 1.00

1. 00

1.00

1.00

1.00

1.00

1.00

1.00

1.00

1.00 1.00

1.00

1.00

1. 00

1.00

1.00

1.00

Weight

Chiffon .—do

—.do

Service Chiffon —do —do

—do.

—.do

Service .—do

.—do

Chiffon —do

.—do

-—doMedium service Semiservice

Service —do. —

—.do

—.do

Chiffon .—do

—.do.

Medium service Semiservice

Chiffon

Semiservice Sheer chiffon Chiffon

Service chiffon Service .—do —doChiffon —do —do- —do —do

.do .do

.do

.do

.do

.do

.do

.do

.do

.do do

do

Semichiffon. do

Semiservice. do

42

42

$1.00

1.00

1. 00

1.00

1.00 1.00 1.00

1.00 1.00

1.00

1.00

1.15

1. 15

1. 15

1. 15

1. 15

1. 15

1. 25 1.25

1.25

1.25

1.25 1.25

1. 25

1. 25

1.25

1.29

1. 35

1. 35

1. 35

1. 35

1. 35

1. 35

1. 35

1. 35

1.35

1.35

1. 35 1.50 1.50

1.50

1.50

1. 50

1. 65

1. 65

1. 65

1. 65

1. 65

1.65

1. 65

1. 65

1. 95

1. 95

1. 95

1. 95

Weight

Semiservice..—. do Medium service Service dodo—

do.—

do—.

do

do. Heavy

Chiffon do.

do. do

Service do.

Chiffon do —

do. do

do - —do

Medium service.

.

Service do.

Chiffon do. dodo

do

Semiservice. do

Service. dodo.—

do —

do

Chiffon —

do

do Medium service Service Chiffon.

..do..

._do_. ..do-

..do.. ..doService

.

doChiffon. do._ doService.

1 125 denier rayon.

2 Ingrain.
4 Miscellaneous Publications, National Bureau of Standards

III. TEST PROCEDURE

The dimensions of the stockings and their various parts, as indicated in figure 1, were measured with a scale when the fabric was

lying flat on a smooth surface, without

tension.

The number of wales were counted

around the circumference of the stocking

immediately below the welt. Some of

these, generally from 8 to 12, were taken

up in the seam and could not be counted.

The number and location of the fashion

marks were noted as an indication of the

way in which the stocking was fashioned.

The thickness of 2 layers of the leg fabric

of the stocking was measured with the compressometer 4 using a circular foot 1 inch

in diameter and a pressure of 1 pound per

square inch. Measurements were made in

three places on the leg fabric, care being

taken to smooth the fabric and not to in- clude defects, fashion marks, and the seam

in the area measured. The average of the

three measurements was taken to be the

thickness of 2 layers of the fabric.

The weight of the leg fabric of the stocking was determined by weighing six specimens, each specimen being 2 inches square.

These specimens were obtained by placing

the stocking on a thin aluminum hosiery

form which had three holes in it of sufficient

diameter to permit cutting out areas 2

inches square with a die. The average

weight of the specimens was expressed in

Figure 1.

Schematic drawing ounces per square yard.

of a full-fashioned stocking The stockings were laundered according t^&fZmX?& £ the procure given m Researcll Paper

dimensions are measured. sxrlbo.

aii measurements are in inches , The laundered stockings were tested on

the hosiery-testing machine described m

Research Paper RP679 6 and the "extensibility ", "recoverability",

and "stretch-endurability" of the stockings were evaluated.

IV. TEST RESULTS

1. SIZE

The orders used in purchasing the stockings specified size 9.5. The sizes of the stockings measured are shown in table 2.

4 Herbert F. Schiefer, The compressometer, an instrument for evaluating the thickness, compressibility, and

eompressional resilience of textiles and similar materials. BS J. Research 10, 705 (1933), RP561.

• Herbert F. Schiefer and Richard S. Cleveland, Factors affecting the performance of hosiery on the hosierytesting machine. J. Research NBS 14, 1 (1935), RP753.

• Herbert F. Schiefer and William D. Appel, Hosiery-testing machine. BS J.Research 12, 543 (1934) RP679.
cl^Snd] Basis for Womenr s Hosiery Specification 5

Table 2.

Sizes of stockings received

(Size 9.5 specified)

Length of foot (inches)

Vs ILLLLUcJ. UI stockings

8.25 to 8.75 - 2

8.75 to 9.25 19

9.25 to 9.75 261

9.75 to 10.25 125

10.25 to 10.75 _ 4

10.75 to 11.25 - 2 The extreme sizes may probably be taken as an indication that some

of the stores overlooked this requirement in their orders. The

intermediate variations are more serious. They raise the question

as to whether or not manufacturers and retailers are using the standard

method of measuring size. 7 Since sizes are designated in increments

of 0.5 inch, the maximum tolerance is thereby fixed. When a customer

specifies size 9.5, it is believed that she could have no reasonable

objection if the stockings received measured between 9.5 and 10

inches, but she might not get satisfactory service from a stocking

measuring less than 9.5 inches. The tolerance should therefore be

plus 0.5 inch only.

2. LENGTH

r Since the purchase orders did not specify length, it was expected

that the stockings received would be of standard length, namely

30 ±1 inch.8 The lengths of the stockings measured are shown in table 3. Table 3.

Lengths of stockings received

(Length was not specified)

Length (inches) Number of stockings

27.5 to 28.5... 342

175

14840

9 307 (73.6%)

28.5 to 29.5 _ 29.5 to 30.5 30.5 to 31.5.... 31.5 to 32. 5

32.5 to 33.5 29.0 to 31.0 These figures indicate that the standard length has been pretty

generally adopted. This single-length standard was adopted to prevent misunderstandings between manufacturers and retailers, and

to obviate the necessity for carrying extra stocks. Under present

conditions, a retailer may be expected to carry six different sizes, in

four weights and twelve different colors, or 288 varieties of the same

item. If three different lengths are called for, making 864 varieties,

the additional financial burden caused thereby will doubtless be passed on to the consumer. On the other hand, criticisms of the present

standard indicate that a certain proportion of the customers are not

satisfactorily fitted.

7 Standardized Method of Measuring the Size of Hosiery. BS Circular C149 (1924).

* Hosiery Lengths. BS Commercial Standard CS46-33 (1933).
6 Miscellaneous Publications, National Bureau of Standards

The document cited carries a footnote to the effect that shorter

or longer stockings can be obtained. It might be advisable to set up

three standard lengths: "Short" (27 inches), "standard" (30 inches),

and "long" (33 inches). Such a procedure probably will satisfy the

demands of the portion of the customers referred to, but may increase

the price of all stockings.

The present tolerance of ± 1 inch should be retained. It is based

upon the precision with which the manufacturing processes can be

controlled.

3. CLASSIFICATION, THICKNESS, AND WEIGHT

The terms at present used to designate the "weights" of hosiery

are used quite loosely, as is shown by data contained in table 4. Table 4.

Classification of stockings received

Number

Weight of sam- Thickness range Thread Gage

ples

Inch

1 0.014 to 0.015, incl.. Not stated Not stated Chiffon 61 0.009 to 0.019, incL. 2 to 5 39 to 51 Semichiffon 2 0.014 to 0.016, inch. 4 42

Service chiffon - ... - 1 0.017 to 0.018, incL. 5 Not stated Semiservice - -_ 9 0.019 to 0.023, incl- 6 to 7 42 to 45 Medium service. 5 0.014 to 0.025, incL. 7 42 Service 31 0.019 to 0.030, incl.- 6 to 12 39 to 45 Heavy service—_ 1 0.027 to 0.027, incl- 10 Not stated The term "chiffon" is generally taken to mean a sheer, fine' semitransparent fabric, of the desired appearance. "Service " denotes

a fabric which is thicker and heavier, in which appearance has been

subordinated to durability. It was therefore decided to see whether or not either the weight or the thickness could be used as a basis for

classification. The relationship between the thickness and weight of the leg fabric was determined. This relationship is shown in figure 2 in which the

average thickness of 2 layers oi the fabric is plotted as abscissa and

the average weight of the leg fabric is plotted as ordinate. The

number of threads in the silk yarn is indicated in the figure by numerals. The approximate linear relationship shown, indicates that it

is not necessary to determine both the weight and the thickness.

Since it is simpler, easier, and quicker to determine the thickness and

since it does not require destroying the stocking, this criterion was

selected for further consideration.

The frequency distribution of the individual stockings with respect

to thickness is given in table 5. It shows at a glance the relationship

between the number of threads in the silk yarn and the thickness of 2 layers of the leg fabric of the finished stockings. It also shows that

there is some overlapping in the thickness of the stockings knit from

yarns containing different numbers of silk threads. This overlapping

may be caused by any one of the following factors or combinations

of them: (1) number of silk filaments in each thread; (2) use of in- grain yarn, i. e., yarn which is degumed and dyed before being knit

into a stocking; (3) number of courses per inch; (4) gage of knitting

machine; and (5) amount of twist in the yarn.
Scbiefer Cleveland.

pl i t f 1

1 t t . 11 i 1

1

1 r t i 1 1 i t i i .010 .015 .020 .025 .030

THICKNESS OF TWO LAYERS INCHES

FigureJS.—Relation between thickness and weight of stockings which are knit from

silk yarn containing different number of threads. The limits for the proposed classification of hosiery are indicated by the broken vertical lines Table 5.

Frequency distribution, of the individual stockings with respect to thickness

Thickness of stocking (inch) Threads

0.009 0.010 0.011 0.012 0.013 0.014 0.015 0.016 0.017 0.018 0.019

2 4 1 3

3 °9 6 27 25

10 9

48

1 4 446

6

5 21 12 2

2 "3-6

L i k. 7

Threads

Thickness of stocking (inch)

0.020 0.021 0.022 0.023 0.024 0.025 0.026 0.027 0.028 0.029 0.030 6 4 "15

2 7 34 27

8«4

*6

13 <U

8 9 2

3

1

9 241 10 5 2

11 2 2

12 2 2

* Four of these values were for stockings knit from 3-thread ingrain yarn and 4 others were for stockings

knit from 3-thread yarn in which the average filament count per thread was 8.

* The filament count of the 7 threads for each of these stockings varied from 8 to 14.

« Four of these values were for stockings knit from 7-thread yarn in which the average filament count per thread was 9.7 and the total number of wales, exclusive of seam, was 347.

4 Four of these values were for stockings knit from 7-thread yarn in which the average filament count

per thread was 12.

* Four of these values were for stockings knit from 9-thread ingrain yarn in which the average filament count per thread was 9.6.
8 Miscellaneous Publications, National Bureau of Standards

The number of filaments in silk threads was found to vary from 8

to 14. The thickness of the fabric increased with an increase in the

average number of filaments per thread of the yarn. Specific in- stances are noted in table 5. Stockings knit from ingrain yarn (dyed in the yarn) were found to be thinner than those knit from ordinary thrown silk in the gum.

Two instances are noted in table 5. These stockings had the appear- ance of having been knit from yarns containing one or two fewer

threads than were found by dissecting the yarn.

The average thickness of stockings with 45 courses per inch was

0.0006 inch more than the average thickness of stockings with 40

courses per inch. The average thickness of 45-gage stockings was

0.0004 inch more than the average thickness of 42-gage stockings.

Laundering increased the thickness by 0.0006 inch.

The effect of twist in silk yarn on the diameter has been determined

by Huber and Macia.9 Their results, which are based upon microscopic measurements, show that for 2 yarns, which differ by 1 thread

(e. g., 3 and 4 thread) to have the same diameter, the twist in the

heavier yarn (4 thread) must be 4 times the twist in the fighter

yarn (3 thread) for 2-, 3-, and 4 thread yarns and must be 2 times

the twist in the lighter yarn for 7-, 8-, and 9-thread yarns. Variations in twist of this order are not common in yarn for women's

hosiery. The effect of yarn twist on the thickness of the fabric as determined with the compressometer would be even much less. It is seen from the above that the thickness of the fabric affords a

reasonable basis for differentiating between the " weights" of hosiery.

On this basis, and on the assumption that the market demands five " weights", the classification given in table 6 is proposed.

Table 6.Hosiery classification based upon the thickness of two layers of the leg fabric of a stocking

Proposed weight designation Thickness of two layers

of leg fabric

Sheer chiffon __ Inch

0. 012 and less.

0. 013 to 0.016, inclusive.

0. 017 to 0.020, inclusive.

0. 021 to 0. 024, inclusive.

0. 025 and above.

Chiffon

Semiservice

Service Heavy service

4. MACHINE TESTS

The hosiery-testing machine 10 consists principally of a pair of jaws,

each about 12 inches long, mounted horizontally, parallel to each

other, and at such a distance apart that the minimum circumference,

that is the distance around the outside of both of them, is 13.3 inches.

The stocking to be tested is pulled over these jaws, which are then

separated to a maximum circumference of 21.3 inches, and returned

to their original position.

This process is repeated at the rate of 60 flexing cycles per minute,

alternately distending the stocking and letting it come back. The

machine plots the load-elongation curves for the fabric ; the curves for

• Silk yarn formation. Am.Silk and Eayon J. 53, 29 (May 1934).

10 Herbert F. Schiefer and William D. Appel, Hosiery-testing machine. BS J. Research 12, 543 (1934) RP

679.
cfievifand] Basis for Women7s Hosiery Specification 9

the first and for the 200th flexing cycles are used for comparison.

The total number of flexing cycles required to produce failure is also recorded.

All stockings were laundered before being tested.

(a) DISTENSIBILITY 11 "Distensibility" is defined as the ratio of the increase in circumference to the increase in load when the load is increased from 20 to 30 pounds in the first cycle of the test. It is a measure of the ease with which a new, but laundered, stocking can be distended. If the

distensibility is low the stocking may bind and be uncomfortable.

The results of tests are summarized in table 7. It will be noted

that the average distensibility for the chiffon stockings was 0.12 inch

per pound ; for the service stockings 0.13 inch per pound. This shows

that the " weight" of the stocking need not be considered in setting a

limit for distensibility. The figures also show that there is no relationship between distensibility and price.

The distensibilities of the 239 stockings tested varied from 0.07 to

0.27 inch per pound, with an average of 0.123 inch per pound.

On the assumption that more than one-half of these stockings were

satisfactory in regard to this property, it seems advisable to select as a limit a figure somewhat below the average. It is therefore

recommended that the distensibility be not less than 0.11 inch per

pound.

(b) RECOVERABILITY"

" Recoverability" is defined as the circumference of the stocking at a load of 30 pounds in the first flexing cycle expressed as a percentage

of the circumference at a load of 10 pounds in the 200th flexing cycle. It is a measure of the ability of the stocking to retain its shape after

being repeatedly distended. A stocking with low recoverability may

be expected to become baggy in service.

The test data in table 7 show that there is no relationship between

the recoverability of a stocking and either its "weight" or its price.

The recoverability varied from 86 to 109 percent, the average

being 97.6 percent. A stocking which could be distended to a circumference of 18.2 inches by a load of 30 pounds during the first flexing

cycle would, after 200 flexing cycles, have so far lost its recoverability that a load of 10 pounds would distend it to a circumference

of 18.6 inches on the average. Since it has been assumed that the

limiting figure selected should be somewhat below the average, it is recommended that the recoverability be not less than 96 percent.

11 This general definition of "distensibility" has been used in this paper instead of the one contained in NBS Research Paper RP753 (see footnote 2, p. 1) because of its greater field of applicability. The rela- tionship between the two definitions for distensibility is approximately linear.

12 The term "recoverability" has been used in this paper instead of the term "elasticity" because the

characteristic evaluated is different from that ordinarily understood by "elasticity." The definition of "recoverability" given above has been used instead of the definition for "elasticity" contained in NBS

Research Paper RP753 (see footnote 2, p. 1) because it can be more readily visualized. The relationship between "recoverability" and "elasticity" is linear.
10 Miscellaneous Publications, National Bureau oj Standards

iO woo CM w--^ oocmoo oowoo . n O Ou3 OIWOO) o o nod

' LO o o o O CN OCM

! + NOON Q0-*O +31 ON <

CM i g^

oo ooi O "3 O O CO 1 +

o Tti o oo

) O O -H

• +CM O

CO CM O^H "t-OOO ' t- • O <M OS CO O O O O •f OO

o +

co~ + Tt< CM O CM CONO g O OJD O-O

OO N N O CM O

+ 1 O O NO

gs

C3 -Q O T3 CD c« £2 O

N CM O O N( o o o o

O CO (1) rtX! t>T3 <»
Schiefer "j Cleveland] Basis for Women 's Hosiery Specification 11

to °

.2 tut) M

•So ~

tJ3 rH . W 51! a ftga

.Si? ° <3 2 § ».-'° gfg-sg

fl e-S o o

a coT3 s

TM ?: : : o

•S ® © ® is ® S

03 Srt H © <» a 1
] 2 Miscellaneous Publications, National Bureau of Standards

(c) STRETCH-ENDURABILITY »

11 Stretch-endurability 11 is defined as the number of flexing cycles

required to produce a failure, that is, a hole or run in the stocking.

It is to be expected that a knitted silk fabric is like any other material

in that it will ultimately fail when subjected to repeated applications

of stress. In service the fabric is stretched more or less every time

the wearer's knee is bent; in the machine it is distended from 13.3 to 21.3 inches in each flexing cycle. Eventually this treatment will cause the silk yarn to break. It is characteristic of a knitted fabric

that the breaking of the yarn will start a run, which continued

stretching will quickly develop into a larger hole. The machine makes one flexing cycle per second. To test 239

stockings to failure, assuming that each might require 5,000 to 10,000

flexing cycles, seemed likely to be very time-consuming. Fortunately, previous experience had indicated that stockings will either

fail at a comparatively small number of flexing cycles or else will last for several thousand. It was therefore decided to stop each test at 1,000 flexing cycles, on the assumption that a stocking which had not

failed by that time would withstand a good many more. The data in table 7 show that 55 of the 239 stockings failed at less than 1,000 flexing cycles. The chiffon group contained a relatively

higher proportion of these than the service group, which might be

taken to mean that 1 ,000 flexing cycles is too high a figure for chiffon

stockings or too low a figure for service stockings. There is no

relationship between stretch-endurability and price.

Since stretch-endurability may be considered a property of major

importance in a service stocking, a requirement of 1,000 flexing

cycles is probably not too high. It is evidently far below the average,

for it was met by 89 percent of the stockings of this group tested.

The consumer does not expect as much service from a chiffon stocking, so there is some justification for setting a lower figure for this group.

On the other hand, 72 percent of the chiffon stockings tested were

able to meet this requirement. This indicates that stockings having

this degree of stretch-endurability can be and are being made, even

in the fighter weights. It is therefore recommended that the stretchendurability of a stocking of any weight be set at not less than 1,000

flexing cycles.

5. COLOR FASTNESS TO LAUNDERING

Stockings are laundered frequently, preferably after each wearing.

Therefore laundering should not change them unduly in color and

appearance. To determine whether or not a stocking can withstand

laundering satisfactorily, it is necessary to have a standard laundering

test. The method given in NBS Research Paper RP753 is equivalent

in severity to perhaps six normal launderings and is recommended

for use in hosiery specifications. The stockings thus laundered

should show no objectionable change in color and appearance.

13 The term "stretch-endurability" has been used in this paper instead of the term "endurability" in order to avoid possible confusion of the characteristic evaluated with resistance of the heel, sole, and toe of the stocking to abrasion.
Schiefer 1 Cleveland J Basis for Women's Hosiery Specification 13

V. MISCELLANEOUS

1. CHECK TESTS

A great variation was found in the results of the different style

numbers of a brand, also stockings of the same style number and

brand which were purchased three months apart from the same store did not give the same results. The stockings which were purchased

at the earlier date had stretch-endurabilities less than 200 flexing

cycles, while those which were purchased at the later date had stretchendurabilities greater than 1,000 flexing cycles. In another instance

a number of pairs of stockings of the same style number, brand, color,

size, and price were purchased at the same time from one store. It was found that part of these stockings (assuming a 14-inch needle

bar) were knit on a 42-gage knitting machine, while the others were

either skimped or were knit on a 39-gage knitting machine. There was therefore no assurance that these stockings were degummed,

dyed, and finished alike. In view of the effect which these factors

have on stockings,14 it is not surprising that the results of the tests on these stockings were not the same. The stretch-endurability of

the 39-gage stocking was 866 flexing cycles and of the 42-gage stocking was greater than 1,500 flexing cycles when the test was discontinued.

Table 8.

Frequency distribution of the stockings with respect to the dimensions of

different parts

Length of welt (in.) Frequency Width of welt (in.)- Frequency Number of fashion marks

.

Frequency Number of wales Frequency Number of wales Frequency Number of wales Frequency

Length of heel (in.)_ Frequency Width of heel, (in.) Frequency Length of high heel (in.).. Frequency Width of high heel (in.)_ Frequency Length of toe (in.) Frequency Width of toe (in.) Frequency. Width of sole (in.) Frequency

1.5

11

18 3454

395

3 445

1.5 2

12

1.5

1.25 3

2

122.75

26

2

30

5. 75 32

2

35022 400

10 450

11.75

41

1.25

651.75

12.50

171

2. 25 863

256

.75

110

2.5

10

139

4

24 355

405

102 455

2

2

189

1. 50

178

292

.75 225

2. 50

1783.25

142

1 189

6. 25

155

10 360

11 410

42

2. 25 155

1. 75 1492.25

157

116

2. 75 124

1.25 83

3.5

159

60

365

12 415

6

465

62.50

33

2

282.50

114

1.25

7

1. 50 5

4 109

75

10 130

370

15 420

4702.75

5

2.75

35

3.25

4.5

13

7

212 111 375

64

425

475

3

1

14

380

71 430

5

3.25 2

"Herbert F. Schiefer and Richard S. Cleveland, Factors affecting the performance of hosiery on the hosierytesting machine. NBS J.Research 14, 1 (1935) RP753.
14 Miscellaneous Publications, National Bureau of Standards

2. DIMENSIONS OF PARTS

In figure 1, various parts are indicated besides those for size and

length. The frequency distributions of the dimensions of these parts

for the stockings measured are given in table 8. Since some of these

parts are style factors, while others are of different importance to

different consumers, it is felt that any attempt to standardize them

might be out of place. The data are therefore presented merely as information.

3. OTHER TESTS

There seems to be a growing demand for information about two

other properties of hosiery (1) the ability of the heels and toes to

resist abrasion, and (2) the ability of the fabric in the leg to resist

snagging. Work is at present under way, both at this Bureau and

elsewhere, to develop methods of test for these properties.

VI. SUMMARY

Based on the above data, the following recommendations are made:

The size of the stocking should be as specified, with a plus tolerance

of 0.5 inch.

Unless otherwise specified, the length of the stocking should be 30

inches, plus or minus 1 inch.

The weight designation of the stocking should be based upon the

thickness of the fabric, using the classification suggested in table 6. The "distensibility" of the laundered stocking should be not less than 0.11 inch per pound.

The "recoverability " of the laundered stocking should be not less than 96 percent.

The "stretch-endurability" of the laundered stocking should be

not less than 1,000 flexing cycles.

When laundered by the method described, the stocking should

show no objectionable change in color or appearance.

Washington, March 1, 1935.

o