I serge the cut edges of my purchased fabric, then throw it in the washer to get rid of any chemicals as well as the sizing. Warm water, cold rinse, no fabric softener. I dry it in the dryer for a few minutes, then hang it over the line. Then i spray it with my own concoction of spray starch--to get that sizing back in. When it's almost dry i iron it. With the spray starch,cutting becomes a breeze.when i see a serged piece of fabric in my stash, i know it is ready to use.