Most of this advice is right on the money. However, I can tell you that even though our matboard comes by truck from Bainbridge and Crescent there are still times that there are dinged boxes. My question is, how bad a ding renders the matboard useless? For example, if you own a CMC you are typically going to have a minimum of 1" of waste on the bottom and left. If the ding is less than 1" isn't the dinged corner the one you are going to place in the lower left? If you are hand cutting mats, do you blank your board first? If so, then which part do you cull out? If you are framing 32x40 or 40x60 prints then I can see some issues, otherwise because of the number of times a board is handled from the manufacturer to the customer, this dings are unfortunately going to happen.