GNU Image Manipulation Program (GIMP, ver. 2.8.14) on a Mac OS. A Image window B Toolbox window C Tool Options window D Layers window E Foreground (black) and Background colours (white).

 
 
  Part of: Montesanto G (2015) A fast GNU method to draw accurate scientific illustrations for taxonomy. In: Taiti S, Hornung E, Štrus J, Bouchon D (Eds) Trends in Terrestrial Isopod Biology. ZooKeys 515: 191–206. https://doi.org/10.3897/zookeys.515.9459