How to Iron on Patches 1. lay out your jacket, sash or backpack and decided where exactly you want the patch to be placed. 2. Place the patch in the position you chose. 3. Heat up an iron. Turn it to the hottest setting your fabric can tolerate. Make sure the "steam" option is turned off, and that your iron isn't full of water. 4. Place a thin towel over the patch. Take care not to disturb the position of the patch. The towel will protect the patch itself and the surrounding fabric. 5. Position the heated iron over the patch and press down. Hold the iron there for about 15 seconds. Apply as much pressure as you can by pressing down firmly. 6. Remove the iron and allow the patch to be cool. 7. For a completely secure patch, use a sewing machine or a needle and thread to secure the patch to the fabric. This greatly reduces the chances that the patch will fall off. 8. Don't wash the article more than necessary. Iron-on patches are meant to be permanent, but they do become loosened over time.