You have to bond the fusible to the fabric well. If it is gummy put more steam and heat to it. In the directions it says to not be afraid of pressing it too much. I had a gummy problem that went away after I pressed it more. Now I just make sure I press it a lot, using steam and it doesn't gum up the needle. Most fusibles use a dry iron. This one uses steam so make sure you use steam. It is one of my favorite fusibles.