I've never heard of crocking before and it's never been a problem for me. Interesting. I do have some vintage, antique quilts that I'll drag out and see what is going on with them, as one is a red star "freedom" quilt done with turkey red fabrics. If anything will crock, it might be this quilt. I do have some indigo blue log cabin quilts too that might cause a problem. I don't have them boxed or wrapped, just on a shelf in a closet, out of the sunlight, but the fabrics are touching each other.