To apply EzeFuse I recommend steaming your fabric (cottons) first and allow to cool (if not prewashed). This helps with any shrinkage that your fabric may have. Then using a dry iron on a medium temperature, press EzeFuse onto the wrong side of the fabric. You do not need to use a high heat. Medium heat should do it. I sometimes have used steam (habit) and high heat and still haven’t had any issues, so it’s pretty forgiving in its application.