I use Madeira exclusively. How is the humidity in the machine area? That
will be a factor and an invisible burr in a needle will cause it to happen
frequently. I used RA once and quit when I had to use a spot gun on an
oil stain. The thread color bled all over the nice white shirts. I just did a
sample run this morning with poly and rayon side by side. I had the rayon
fray up 3 times on a 10,000 stitch design. Polyester ran fine.