A merrowed border patch means that a special type of thread is sewn around the edge of the patch to sort of seal the edges of the patch. A lot of our customers believe that merrowed border patches look a lot cleaner, because there is no thread that puckers out on the edges of the patch.
The choice of choosing a merrowed border or stitched border is really one of personal preference. The only set rule is that a merrowed border generally does not look good on 100% custom embroidered patches, but again we have come across customers that like merrowed borders on 100% embroidered patches. Check out one of our blog posts about borders to get another opinion on the border debate, or check out our special options page to read more about merrowed borders.