Very interesting thread and one that I am learning new ideas from. I have used mostly cotton for FNQ. My favorite is King Tut from Superior. However, I have started to branch out with polyester. I think I like it and will use it several more times before making any hard conclusions. We need to be open to new ideas. However, we need to understand the characteristics of the fiber content. Rayon, a cellulosic fiber has no strength but wonderful color absorption which makes it vibrant. That is a tempting combination but should be left to embroidery because no strength is needed. I have used a gold thread from Superior (King Tut) in a quilt and it was very pretty.