I have done a couple of these jellyroll quilts. The first one I left the 40 strips whole except for cutting off 18 inches on the first strip. On that one I wasn't real happy with the "stacking". On the second one, I cut 20 of the strips in half, and the other 20 strips I cut into approximate one third length strips (13"). I then put them all in the dryer on air only to mix them up. This made for a better look that was much scrappier. I posted pictures of both on the thread I started which is called jellyroll 1600 if you would like to take a look.
Here is a link to those pictures.
http://www.quiltingboard.com/main-f1...s-t199536.html