My main reason is because it seems odd to me to wash out sizing and then put lots of starch on it to piece it! With today's technology, there isn't a lot of shrinking on most cottons & since that's all I use, it's just personal preference. Plus, living in a camper, I have to use a Laundromat and that would get very expensive! I usually wash the quilts before I give them away unless they're in a particular hurry & then I just add Color Catchers in case something runs.