Hi Sue
I stopped buying charm packs unless they say prewashed. I spent good money on some and they frayed and shrank like crazy. I did make a quilt without washing first using the charm pack. It was a baby quilt and I worried it would fray or come apart. It is OK but I think because it was small. I tried delicate and the pillow case method, even by hand. It all depends on the quality of the fabric they use. Good luck with it. Lelia