Morris would sometime define areas to work within, but of course he could only guess if he was able to get the marks where he had directed, his closeness or distance from the indicated areas is very easy to see as he has indicated the areas with geometric precision, thus highlighting the nature of the hand made marks. He takes us back to first principles, some of our earliest drawings are the imprints of people's hands left on cave walls and therefore often done in the dark.
These drawings also act as records of performances, his work holding a line so to speak, between performance art and drawing.
Because of the central position that these drawings take within recent drawing theory there is a fair amount of writing available in support of the theoretical issues surrounding these drawings. Therefore they could make a useful COP3 subject. For example see