Frequently Asked Questions (FAQ):
The 'film' on the back of your patches is the state of the adhesive until heat is applied. [Note: Some patches may have a white paper backing: these require no ironing. Remove the paper before carefully placing the patch exactly where you want it to stay. These can also be ironed on for added security.]
Remember, if possible, to apply a warm, dry, iron to the back of the fabric rather than directly on the face of the patch. If that's not possible due to the fabric material, insert a piece of cotton cloth over the face of the patch and iron onto it. Check adhesion after 30 seconds. If not satisfactory, give it another 30 seconds. If still not adhering, gradually increase the heat of the iron as necessary.
Also, it's best practice to 'tack' down the corners with a single stitch or two, if possible, to prevent curling due to wash and/or wear.