If I have learned anything from my years as a jeweler, it is that the human eye is pretty lousy at determining if something is straight if there isn’t a straight line to check against. That is what makes a simple tool like a square so indispensable at your bench. You can use it to check your bezels and say goodbye to the aggravation of crooked bezels forever. It also has a handy ruler printed on its edge, so helpful when I can’t find my ruler! I love tools that are multipurpose, it cuts down on the clutter on my bench.