I have made a lot of crib quilts - all washable, of course. I wash what ever fabric I find that has a design I like. Then I iron the pieces -if they don't shrink, nor stick to the iron-and look well with only a pass over from the iron, I feel free to use them. I don't worry about what they are made of, only that they will wear and wash well. Many mixtures of materials are better than pure cotton, I find. I do use cotton flannel for backings, as it stays so nice and soft. My great grandchildren love them.