I do not prewash all of my fabric because i also like the crinkle look. However, I do cut like a 4 inch square of each fabric, put it in a hose bag and toss in both the washer and dryer so I can see if any of it fades and what the degree of srinkage will be. I like to do this because I rarely use the same designer/mfg company for all of the fabrics I use in a quilt.