Just for clarification.... You do not need to get permission to display a quilt that you made from someone's pattern.
Copyright in the context of quilts, fabric arts, and patterns is for the pattern only. The actual physical pattern that you purchased. The quilt that is made from that pattern is in no way copyrighted. Quilts, like clothes, are useful items and cannot be copyrighted. Even the quilt the designer made while designing the quilt is NOT copyrighted work. Only the pattern. And even then, most do not go through the process of formally copyrighting their work.
As a quilter.... I had this conversation with my Intellectual Property Professor in Law School. Think about this from an economic stand point. People who design quilts or other patterns want to put their name out there. By telling you that it is required they are forcing you to give attribution or free advertising for their product.... You do not have to.
Personal use is absolutely the foundation of copyright. Copyright infringement happens when you use someone else's copyrighted material for commercial purposes. Every person who has VHS recordings of movies that they taped off of tv is not in violation of copyright if it was only for personal use. It becomes a copyright issue when they attempt to sell those tapes.
There is a slightly longer copyright run down. The links that Iceblossom posted above have some very good information. Here is one more link for you to look through that addresses in more detail the display of quilts:
http://www.tabberone.com/Trademarks/...s_Issues.shtml