I don't claim to know how sandpaper is made or which materials/processes make one brand better than another. That said, these Jet sleeves have the abrasive perfectly distributed, don't load up, and last a very long time. About 100 board feet later, the first set (different diameters - first sleeve of each) is still going strong. I can't say the same thing about "D" brand, haven't used and can't find 3M brand.
