Do's and Don'ts for Iron On's
ALL manufacturers recommend sewing on all iron on patches and appliqués for permanency.
• Unless your application requires frequent hot water washing and drying, almost all iron on patches can be safely washed and dried. Just apply a bit of common sense. The amount of heat that applied a patch will loosen a patch. Generally patches will survive the amount of heat your fiber can take (exceptions are vinyl, sequin, and "puffy" patches - see below for more details). Here's a list of general do's and don'ts:
• DO NOT APPLY iron on patches to waterproof rainwear, highly elasticized fabrics, leather, rayon, nylon or similar fabrics. If unsure, test your fabirc with an iron on a hidden seam or hem to see just how much heat the fabric will accept without damage. Cotton and polyester fiber blends work best. As new fibers are constantly being developed, be sure to test! REMEMBER, you can always sew on an iron on patch except hot fix. 
• ALWAYS turn the garment inside out during washing. This is especially important for hot fix iron on's as washer and dryer walls, and agitators can damage individual stones. See cleaning instructions for details.
• NEVER use HOT water or a HOT dryer or you risk loosening the patch or studs. You can TRY ironing them on again, but most likely if they begin to loosen, you will have to use a fabric glue to re-attach them.
• ALWAYS try to iron onto only one layer of fabric. If you have to iron through two pieces of fabric "stacked" (like on a t-shirt or jean leg), put another piece of clean fabric between the two layers or use a Teflon sheet (available at craft stores) between them to ensure no glue passes through to the other side thus bonding the two fabrics! This is especially important with sheer or open-weave material. The adhesive used for iron on's is highly "sticky." Once it cools you may be able to reheat and separate the fabric, but most likely it will be permanently damaged.
• If your fabric feels stiff, like it may have a lot of fabric sizing. You should pre-wash it. The goal is for the glue to melt into the fibers that make up the fabric. Sizing is a temporary stiffener. Like starch used in collars in the "old days" that additive that can interfere with the ability of the glue on the patch to adhere to the fiber. If the glue can't adhere properly, it will fall off. Be particularly cautious with old chintz fabrics for example.>
• LEATHER & VINYL: Do not attempt to iron patches onto any kind of leather or vinyl material. They are not designed to take the heat needed. Find an appropriate glue at a craft store, and glue the patch into place. A word of caution - it may take some experimenting with the glue. See the note below. about gluing patches.
• After time, if a patch or stone on a hot fix comes loose, you can reattach easiest with fabric craft glue for hot fix appliqués', or iron on patches; or with a few stitches on embroidered patches.

Gather together the following items:
• A household iron (preferably one without an auto-shut off)
• A pressing cloth (a thin piece of cotton or muslin fabric or smooth, lightweight cotton towel or piece of old t-shirt works well). A thick single sheet or doubled up if thin, dry paper towel works fine.
• A firm piece of cardboard covered in aluminum foil or other firm heat-safe backing material.
Following are detailed steps to adhere an iron on patch. It is not hard and 99% of the time the process is quick and very easy. Difficulties usually only arise with very unusual fabrics or faulty household irons that don't reach proper temperatures.
1. Set iron to "dry" not steam setting.
2. Pre-heat to cotton setting (or if unsure of your fabric, one or two settings lower).
3. Position your patch as desired and cover with the pressing cloth.
4. Place the backing underneath between your garment or project and the iron board. The backing board helps reflect heat back to the patch and garment rather than drawing heat into the ironing board cover speeding up the process and ensuring a flat, secure bond..
5. From the front of the patch, press the iron flat in an up and down, vertical motion (do not move back/forth/around) for 25 to 40 seconds to tack the patch in place using the center part of your iron.
6. Turn inside out or upside down (if possible) and still using the pressing cloth, repeat from reverse side for 30 to 45 seconds.
7. ALLOW the patch and your item to cool, completely.
8. Test an edge of the patch with your fingernail to ensure it is secure.
9. If not, repeat increasing the amount of time 10% - 20% each time taking care to ensure the patch and fabric are protected.
Warning: Do not remove the patch if you fail on your first attempt or you will damage the adhesive. Just repeat the steps with additional time. Some household irons just don't get hot enough as they do not have temperature gauges. The goal is to melt the glue into the fiber without scorching or burning the fabric or the patch.

North West Washington patch