Handmade Egg Happy Baby with Iron-on Patch Patch Size: select size (inches) wide Made to ready to iron on! Easy to use! You can sew it on or use a household iron for your garment, bags, or accessories. For Iron-on method: Use medium/firm pressure - 270 degrees Fahrenheit Too much heat will melt the plastic, too little heat won't activate the glue. Temperature must be 270 degrees Fahrenheit. Your Patch will not adhere properly if you don't use the correct temperature. You cannot iron on patches to leather or nylon or any other material that might scorch from the applied heat. Enjoy! :)