I've used Sulky rayon for FMQ. While it looks great and I didn't have any problems with it, I wouldn't recommend it for a quilt. I've used it extensively for wearables, but they don't get washed. I used it to quilt one quilt that I use quite a bit. It's been washed a lot and the rayon thread is not start to break so I guess I'll have to re-quilt it with something else. eeeeeeeek!