Visualisation

LINE DRAWINGS

For technical / botanical illustrations, I prefer to use black ink mapping pens (Rotring type) of different widths, drawing on translucent mapping paper. The paper allows tracing, and mistakes can be corrected very precisely by scraping with a scalpel, and also using an eraser.

The diagrams can be scanned as black and white TIFFs at 300dpi for electronic use and printing. I have not found it possible to draw satisfactorily directly on the computer, even using a tablet and pen. However, corrections can be made to the original quite easily on the scanned image using a graphics program.

Such TIFF files will print out excellent quality line art, but the image will not display well at reduced scale on a computer monitor. The drawing will seem incomplete with missing, washed out lines, especially if they are fine (e.g.1mm).This is because the monitor resolution is less than the printer, and some fine lines do not show up on the screen. The solution, for on-line viewing, is to convert the TIFF to greyscale, then apply a so-called Gaussian blur filter. This has the effect of making the fine lines wider, and thus showing on the screen. The image can be saved as a compressed JPEG.

• Pine life cycle (simple line art)
• Seed storage (shading techniques)
• Seed sampling techniques (line diagram)