From their website:
We sometimes get game mats that are slightly less than perfect, or have customers change their order after we have alreday produced their custom game mats.
For example: On July 22nd, we accidentally made a European Fields game mat with 1.5 inch hexes that was 45×71 inches in length, rather than the standard 45×72 inches in length. Other than the length, this is a perfect game mat.
The condition of the game mat is listed, but in most cases, the imperfections are very minor.