I’m going to be starting my Grade 6 Exploratory on guitar after spring break. There are 4 classes of 30 kids each; I see each class once a week. I would like to try labeling the fingerboards to help kids locate Em, simple C, G and so on. There’s a lot of regression between one class and the next, and I thought this might hasten things along. Stickers work as long as they stick (and ideally, kids will eventually remember – we hope). Has anyone else out there tried any other materials for labeling? I’ve used finger nail polish to create position marks on the fretboards that don’t have them, but that is pretty permanent.