I did crosstitch when I was a child and the ink did come out after washing. It is a problem with storing undone patterns for any length of time because any damp conditions will cause them to fade. Light, also, will do it. I would finish the blocks then wash them in cold water. I have a pair of pillow cases I got at a yard sale a few years ago and one of them has faded. I'm thinking of washing them and then ironing on a new pattern. Don't really like the one on them anyway. LOL