Once upon a time (1985 - 2000) I had a small embroidery business. I embroidered logo's on golf shirts. These shirts have been laundered over and over again. The logo's are still just fine. When I started quilting I used the thread I had from my embroidery business if I needed a special color. So far those quilts are still being used as well. I don't use the rayon thread too much for quilting only because I was told it wasn't strong enough, though I never personally had problems with the thread breaking while I was using it and I always use a hot iron. Just some food for thought!