I drew these artists at the Art School at Old Church friday evening with a watercolor brush on stonehenge paper.
If you are at a long pose session and have already moved around the room for different views of the model, draw the artists. As they draw the model they hold a pose also. Putting several figures in the picture plane add an interesting flow to your composition.
When I draw on an ipad my finger or stylus glides. When I draw on vellum with tooth and charcoal, there is friction and drag between the paper and the charcoal, which slows my line down a bit. This is the case whether I use vine charcoal or a Generals HB charcoal pencil sharpened to a very fine point. If I am feeling rusty or have not been drawing for a while, I can find my way back to it with charcoal on paper without having every hesitation show.