A function that allows you to draw on top of a PDF session created with Alchemy.
The idea is not to develop these sketches further so much as to add to the drawing process. A timer could be used to go through each page, draw on top of it then automatically save it out.
Doing this again and again and again could result in some interesting work. As each time you will be drawing with an entirely different canvas, it could prevent the staleness associated with looking for too long at the same image.
