My green cutting mat is probably 10 years old.
It's had a slight buckle or lump to it most of that time because of something careless I did way back then..although it didn't effect using it.
I've been in a hurry to finish this quilt so yesterday, instead of running back and forth between my cutting mat and ironing board, I flipped the cutting mat over and quickly ironed my fabric on it. Then, to get my grandkids stack of books out of my way, I put them on the mat (The distance to my ironing board is only a few steps, but I'm also lazy...).
Anyhoo, the combination of the heat and weight must have been just right because this morning my matt looks brand new.
I was going to use the next 50% coupon from Joanns to buy a new one but now I don't think I will.