I starch my yardage just before I use it. My yardage gets washed when I bring it home, but I don't iron and starch it until I am going to use it. (Maybe because I am lazy, but I only want to iron once.) I also wash my pre-cuts because the chemicals on the fabrics can irritate my fingers, so I will starch them too before using them too. But as Prism99 said, they can shrink. I just had a kit that had 9 pieces of 1/3 yard each and I washed them and each piece shrank. It was a bit of a shock, I had to adjust the pattern which didn't thrill me but it's okay. I was just surprised because the fabric was a good brand.