I did a lot of research when I was looking for a clamping system for picture frames. I kept coming back to Ulmia and decided to give it a try. They look good but just don't work with the woods I tested them on: maple, oak, pine, crimsonheart and cherry. The springs have nail-sharp ends which, when clamped with the lightest pressure and still managed to miter, punched various holes and notches in the wood. I even tried one on the lovely wooden box they came in and it crashed into the side. (Has…