I don't know if this has a name, but my teacher called it mark making. This is his website - http://www.brookelarsen.com
To prepare us for the project, we had to draw in our sketchbooks a # of drawings. They all had to be of different marks. For example, one is drawn using only dots and another using only horizontal dashes.
This didn't take the whole semester. I can't remember exactly how long it took since it happened close to 4 years ago. I'd say it took about 2 - 3 months. We worked in class, but not always. We always had to do a certain # of boxes at home.
After everyone was finished, all the portraits from all of my teacher's classes were hung in the hallways of the school. There was one girl who punched holes in magazines and used the little circles as her mark. Instead of overlapping, she placed them an equal distance from each other. There was a boy who used a stamp also, but only black ink. His stamp was his birthdate. I think he skipped the whole box thing because his stamp was long. This teacher does the same thing with his students every year. He encourages everyone to be creative and different. Just last year, somebody used hair in his!
I hope some of you will try it and post the results. I'd love to see.
Thanks again for your comments!