I don't prewash the smaller pieces but I have hand-washed some fat quarters because I didn't like the smell. I usually don't wash fabric I purchase in my LQS. However, if I buy fabric in estate sales or eBay I always wash the fabric immediately because I do not know where, when or how it was stored. Perhaps I am overly sensitive to orders, but if I feel the smell of the fabric disturbs me then I know it will disturb the recipient of the quilt.