as usual, there's a great deal of misinformation posted in this topic. also a great deal of convenient misunderstanding.
a pattern that provides instructions for making a truly unique and orginal design absolutely IS protected by copyright law.
if you see a quilt somewhere and you know the design is unique and original, the quilt - which constitutes publication - is protected by copyright law. you do not have the right to copy it.
a derivative that is only 5% different from the unique and original design is NOT safe from prosecution for violations of the copyright law. the differences have to be so significant that no reasonable person would look from one to the other and recognize them as the same or more than slightly similar. there is no fixed percentage written into the law.
when a design uses blocks from the public domain, then the layout can't be copyrighted. however, the instructions and images in the pattern absolutely are protected.
if you didn't design it, then don't assume you're entitled to copy it just because you like it. take the time to find out whether or not it's legally protected.
put yourself in the shoes of the person who designed the quilt and act accordingly. to ask if you can copy it is a courtesy that might be considered a compliment. to just help yourself might be stealing. who considers that a compliment?
if the rule of "if you don't want it copied, then don't show it to me" takes hold, then we'll see blank walls in galleries and quilt shows will become a thing of the past.