Paper or Plastic?

Paper or Plastic?
Medium: Charcoal & Conte Crayon
Canvas: Drawing (medium) Paper
Size: 24"x 18"

This was one of my still-life assignments in my Drawing I class. To draw crumbled paper bags. I have to say it was tough... but I think the middle paper bag really came out good. I think what I like most about it... is the dynamic shadows... and the way I put it so that it looks more geometrical compared to the bag in front of it. That one looks more organic and therefore does not really resemble a paper bag.

So I guess all I can say... Paper or Plastic? hee