Pen and ink illustrations of plants are found most often in field guides. They convey a great deal of information and are attractive works of art, even though being a “work of art” might not be their primary purpose.
Learning how to draw in pen and ink can be a challenge. Figuring out how to make marks in the proper order to create the intended effect takes some thought. After all, ink is so, so …… permanent.
One can easily find a nice selection of instructional books about working in pen and ink. Resources dedicated to drawing in the sciences, however, are a little more difficult to find but they are out there. Take for example Biological Illustration: A Guide to Drawing for Reproduction by Claire Dalby and D. H. Dalby.
This 14-page paper is a helpful introduction to drawing in pen and ink. Don’t let its age (32 years) cause you to doubt the value of the information it has. While today there may be more convenient pen and ink tools at our disposal, not to mention technologically nifty ways of creating pen and ink-like drawings with apps, nothing beats learning from people with years of experience behind them.
In their paper, Dalby & Dalby (1980) address many interesting topics. Topics such as creating diagrammatic and naturalistic images, working from dried or preserved material, and reproducing line drawings for publication. They include in their paper a 9-page guide to drawing in black and white where they discuss: dots, lines and tones; pure line drawing; tone; dots; hatching; artificial tones and tints; pens; pencils; brushes; paper; spare paper; ink; white paint; light boxes and tracing tables; linen testers and proportional dividers. I think you will find the section about hatching of particular interest. In this section, Dalby & Dalby (1980) present the fruit of the opium poppy drawn seven different ways. Here you can learn how line drawing, stippling, hatching and a combination of dots and lines can affect the appearance of a specimen.
I think you will also enjoy the troubleshooting section in which they address drawing challenges. Here Dalby & Dalby (1980) offer suggestions about how to create smooth surfaces, thin subjects, hairy subjects, small subjects, complicated subjects with too much detail, colored subjects, spirals, and intricate symmetrical subjects.
Another helpful section is the one in which the authors address printing techniques and their limitations. In this section, they provide invaluable insight that will help you plan line drawings for publication.
This paper is a wonderful addition to any drawing library. It is available online for free from the Field Studies Council. Click on the link below and scroll down to Volume 5, Number 2.
Dalby, Claire and D.H. Dalby. 1980. Biological illustration: A guide to drawing for reproduction. Field Studies 5(2):307-321. Web. <http://www.field-studies-council.org/fieldstudies/date.htm> [accessed 20 November 2012]