I've been thinking a lot about ways to better grade ISNs and I think that stamping them will make my life much easier. I'm thinking that these stamps from Office Depot would be perfect. Self inking is a must because I'm not carrying around an ink pad and there are a lot of options with this set so I can switch up the stamps/colors each time I mark something. Or maybe use one stamp specifically for things that are late. The details are still a work in progress but I think I'm pretty sold on the stamps.