"The sticky back gums up the needle".......includes both machine and hand needles....exactly why I only use the sew on type. I try to sew by machine whenever I can without the stitching showing in the "wrong place", otherwise I sew by hand. I quit buying that sticky stuff long ago and never looked back. Well once when I found some Velcro that was allegedly an iron on type that did not need stitching. Allegedly being the key word, if you never pulled it apart, it worked fine.