Traditional black and white media: ink and graphite pencil
Ink is a high contrast medium that produces shading through stippling (carefully spaced dots individual dots), or lines. Every mark made by the illustrator is in a pen and ink drawing is either black or white - never gray.
Graphite pencil is a continuous tone medium that employs the full range of very subtle gray tones.
Scientific illustrators are beginning to create images directly on the computer rather than using traditional media, however, most artists still use traditional media to prepare detailed illustrations requiring a great deal of subtle detail.
|The illustration of ostracodes on the left, prepared by Smithsonian artist Lawrence B. Isham under the direction of Richard H. Benson, is an example of the pen and ink stipple technique. The illustration on the right of a fossil mammal, prepared by L. Isham under the direction of Lewis Gazin, is an example of the graphite pencil technique.|