I’ve done many blind drawings in my sketch books. Sketch books are supposed to be studies for future paintings or larger scale works.  In the pen and ink/watercolor experiment below, I used two of my previous sketches (Man with Hair Too Small for Rest of Face and At the Eye Doctor’s). I drew the outlines on the watercolor paper, while looking at the sketchbook figures (a blind drawing of a blind drawing), then I used blue watercolor to accentuate the figures and gray to tint the glasses.

Eye Clinic Waiting Room Sketches Re-Drawn and Painted with Watercolor
Pen and Ink and Watercolor
16″x12″ 140# Cold Pressed