I broke in a brand new one today. It takes a bit more care than the metal 4x5 holders that you can run over with your car. Like anything with glass plate, I need to be careful with it. Having 2x the glass in the holder is the way to go. I also modified 3 Graphic film pack holders. By the time I added up the cost of buying the holder, having an insert 3D printed and the time involved, a single holder cost me about 1/2 the price of one of these. It only holds 1 piece of glass and it’s bigger and heavier. Now I have both. I needed to try modifying these and now I know. Just my .03