This is always an interesting topic because so much seems so gray to me. I noticed that so many pattern are tweaked a little from other patterns. Most of the quilts I made were using two patterns that were produced by a small LQS. Since I allowed them to photograph my quilts. I never worried about selling them. I even had them for sale in their craft fair. I have always assumed that it is the fear of having items massed produced. I try to change a pattern a bit and then I feel free from any limitation. I don't like seeing the conditions printed on the selvage of the fabric.