I've bought four FLG Mats from you (Summit, Swamp 2, Moon, and Terraviolet in 4'x4') and opened them upon arrival. Summit turned out great while the other three are warped/lumpy and won't stay flattened. I don't know if it's due to terribly storing your backstock of mats as they arrived quite compact (each tri-folded) in a small box. Didn't seem to affect the Summit mat so I'm not so sure if that's the cause, but I'm left baffled at this quality.
Considering the amount of money I spent on each mat and your no-returns policy for opened products means I'm stuck with them. I'm not inclined to purchase more from you nor recommend you to those I wargame with at my FLGS. I've attempted to contact FLG Mats regarding maintenance and care from their mats I got from your store, and they've yet to respond to me.
I used to have positive things to say about Aries Games & Miniatures, but dropping nearly $300 for unusable product (save for the Summit mat) has left me disappointed and shopping elsewhere.