i preshrink all my cotton batting and the poly is no problem at all...i put the cotton (unfolded but in a large bag made from a twin sheet, folded in half from top to bottom and sewn on three sides. i put batting in and then baste the 4th side with the longest st i can and with the top tension loosened 1 or 2 numbers...this way the bobbin thread pulls out in seconds and then the top thread does the same.... i keep the bag, of course...all cotton batts need to be shrunk...the cat orders can be helped by using oxyclean and/or borax...