Custom patches are a perfect way to take your leather jacket up a level, offering an individual appeal in the process. If you are looking to customize that excellent leather jacket with some eye-catching custom patches, but don't want to bother with sewing, be warned; iron-on patches are not the way to go.
Iron-patches and leather go together about as well as flip flops on an ice skating rink. The best-case scenario of adding an iron-on patch to your leather goods is that the patch simply won't adhere. However, the worst case is that you could damage or ruin your jacket.
Leather doesn't deal well with high temperatures, and the iron temperature needed to melt the glue used on custom iron-on patches is too high. Leather is also too slippery for the adhesive, which is not formulated for the surface material.
If you're lucky, your patch just won't stick. If you're not so fortunate, you will scorch or burn the leather, even possibly dealing with blobs of partially melted glue. Faux leather is out too. Faux leather is prone to melting under the temperatures needed to glue patch. This same rule applies to nylon jackets as well; which can result in a destroyed garment and a rather messy iron.
If you are dedicated to the idea of adding patches to leather, real or faux, or even nylon, the only functional alternative is the traditional combination of needle and thread. However, for those intimidated by the idea of sewing, you can find a local tailor shop that can do it for you for a small fee. Get your patch appropriately attached and make that garment your very own!