I was interested reading this thread. I have been in love with crumb blocks for some time now. I think that true crumb blocks are made with smaller scraps (not that it really matters) and that larger blocks made in this random fashion are more along the lines of the old crazy patch blocks??? I make my blocks 3 1/2" square and if I'm making larger blocks, I put smaller squares together. My favorites are the random scrappy ones, where I just pick colors at will.