Im also in with ya on norton ,stuff is great, but i do have a 3m story. i had a job once cleaning out houses that had been forclosed on, well during one of these jobs i found an old pack of sand paper, the pack cover had minnesota, mining and mineral company on it, it took a couple of days before i realized that was 3m, i dont know how old it was , but im guessing pretty old, well that stuff lasted for years, by far the best sandpaper i had ever used, i wish i could find a case of that old stuff.