One more tip: Sometimes when you load a backing one side sags. The easiest way to remedy that is to roll the backing back and forth a few times, all the way from everything on the takeup roller to everything on the bottom roller, keeping the backing taut the whole time. You'll see improvement each time you roll it until there's no more sagging. I don't know why that works, but it does. And I don't know why the sagging happens, either, but it does, lol.