Unless I buy a precut kit (rare), I always wash my fabric. In the summer I line dry, in the winter it goes in my dryer - no fabric softener. I fold it carefully and put it with my stash. When I am ready to use it, I press it with starch. Reasons: washing - I hate the thought of the pesticides that are sprayed on fabric in the warehouse coming into my home - allergies and possible carcinogens; bleeding - I know that they dyes of today are good, but I frequently get some lovely colors floating around in the rinse water and I would be so mad if a finished quilt bled and ruined all my hard work! Starch puts some body back into the fabric, making it a little (or a lot, depending on how much starch I use) stiffer and therefore easier to cut and piece, and really reduces the stretch when I am working with bias edges. Starch also helps my seams lay flatter and I don't get so many flipped over seams when piecing blocks or putting blocks together.