Creating HighQuality Botanical

Illustrations by

Using a Flatbed

Scanner and Adobe

Photoshop1

By Christopher Ross, Natural

Resource Specialist

BLM Nevada State Office

Background

Accurate and reproducible illustrations of plant specimens are

commonly required for field

guides, monographs, reports,

posters, and educational materials.

Although skilled illustrators remain

in high demand, they are increasingly rare, and their products can

be expensive and time-consuming

to produce. Accurate, reproducible,

and artistic illustrations of plant

specimens can be created quickly

by using a flatbed scanner and

image manipulation software such

as Adobe Photoshop1 (Figure).

The results can then be printed to

paper or exchanged and incorporated electronically into word processing programs, presentation

graphics software, and Web sites.

Because of the speed with which

illustrations can be created, several

illustrations of a species in different life cycles or seasons can be

combined.

Discussion

The process begins with obtaining

a representative sample of the

specimen to be illustrated. The

sample should contain as many

components as possible, including leaves, buds, flowers, and

seeds or fruits, even if the last

three must be collected separately.

Keep the sample uncrushed and

moist between collection and

scanning to avoid loss of plant

parts. Ensure that both the scanner

glass and cover are clean and free

of spots. Arrange the specimens in

a compact, lifelike, portrait orientation so that both sides of the

leaves are against the glass. Flowers

may be arranged so that some of

them are flattened open against

the glass, while others are shown

in side view. A small ruler may be

included to indicate scale. Close

the scanner lid gently to avoid

distorting the specimen arrangement. If necessary, a small object

may be used to prevent the lid

from closing too tightly. Drape

an opaque cloth, such as a raincoat, over the scanner to prevent

ambient light from entering under

the lid. Scan the layout at medium

resolution, then import the

image to Adobe Photoshop and

open it. 

Perform the following steps to

create a high-quality illustration:

• Crop the image to include

only the specimen. Click on

the dashed square box on the

upper right of the left side

tools. Draw a box around the

image with the cursor, and

then select Image→Crop

from the top menu bar.

• Convert the image to black

and white. Select the top

menu bar commands

Image→Mode→Grayscale

and click OK to discard color

information. (This step may be

omitted if color illustrations are

desired.)

• Adjust the shading. Select

Image→Adjust→Levels from

the top menu bar. Click on the

white eyedropper that appears

in the lower right of the popup

box. Next, place the cursor on

a part of the image that is only

white background and click.

Then use the cursor to move

the triangle at the lower right

end of the histogram curve

inward (right) until you have

eliminated most of the flat portions of the histogram curve. If

there are flat portions on the

right end of the curve, use the

right side triangle slider to

adjust them inward. You can

experiment with the middle

slider to modify the midtones.

• Adjust the brightness and contrast. Select

Image→Adjust→Brightness

and Contrast and

Image→Adjust→Curves. A

little experimentation will give

quick insight into these commands. 

• Save the image. If it is intended

for use in text reports or layouts, it should be saved as a

TIFF file. If the illustration is

for Web use, it should be saved

NO. 59 DATE 11/12/02

Range

Forestry

1References to specific products or services are provided for information only and do not constitute endorsement or

warranty, express or implied, by the BLM, USDOI, or U.S. Government, as to their suitability, content, usefulness,

functioning, completeness, or accuracy.

Resource Note 59

page 1
Resource Note 59

page 2

as a JPEG file. The JPEG file

format can be used for e-mail.

These choices are available on

the drop-down File type menu

that appears after File→Save

As is selected.

Editor’s Note: During publication

of this Resource Note, the author

indicated that the technique

described also works well for mineral and fossil specimens.

Contact

Christopher Ross

Natural Resource Specialist

BLM Nevada State Office

P.O. Box 12000

Reno, Nevada 89520-0006

Phone: 775-861-6571

E-mail: c1ross@nv.blm.gov

Range

The Bureau of Land Management Resource Notes, which are posted on this

Web site (http://www.blm.gov/nstc/resourcenotes/resnotes.html),

are early announcements of technical and informational

topics for BLM personnel and their customers. Information

contained in this Resource Note has not been 

peer-reviewed. Conclusions and opinions expressed herein do not necessarily represent

those of BLM. Use of trade names does not imply U.S. government 

endorsement of commercial products.

Technical Editor - Deborah Harris (Debbie_Harris@blm.gov)

Science Editor - Brian St. George (Brian_St_George@blm.gov)

Graphic Designer - Ethel Coontz (Ethel_Coontz@blm.gov)

If you would like to prepare a Resource Note for electronic

distribution, or if you have an idea or can suggest an author for a Resource Note, 

contact the Science Editor (e-mail: Brian_St_George@blm.gov; phone: 303-236-1930)

with the topic and the name of the writer, including 

mailing address, phone number, and e-mail address.

Thank you for your interest in Resource NoteS.

Figure. Illustrations of mountain mahogany, Cercocarpus ledifolius Nutt. (left), and western juniper, Juniperus occidentalis

Hook (right), were created by using a flatbed scanner and Adobe Photoshop.1