We are a group of 150 artists and illustrators that share work and techniques
https://www.facebook.com/SketchingWorkshop
we often “play” challenges like this in which we limit the materials and try to come up with something creative, then play a guessing game to see who drew what.
We call it Sherlock. In this case, we limited the challenge to just a few list of materials and one color
Boston Sketcher 