Why Some Patches Curl and How to Prevent It
https://wiki-triod.win/index.php/A_buyer%27s_checklist_for_ordering_patches_for_a_small_brand
You sew or iron on a new patch, it looks great, and a few washes later the edges start lifting and the whole thing cups like a potato chip. Curling is one of the most common complaints about custom embroidered patches, and it is rarely random