HEATSEAL: Another word for iron-on. Allows you to apply your patch onto a garment using a home iron. If you are planning to wash your garment more than 50-80 times after the patch is applied, it is recommended that the heatseal only be used for pre-placement before sewing, and then followed up with a few tag stitches along the patch to hold it in place longer. NOTE: Heatseal will NOT stick to nylon.?hook and loop: One (hook) side or both sides are available.?ADHESIVE: This is a peel and stick backing to hold a patch is place for a single event. Will not hold up to machine washing. If you desire your patch to stay in place permanently, go with the heat seal option, or plastic and sew your patches.