Not much difference, I would say. A DMT that is brand new usually has some "proud" diamond particles that sit high in the matrix and leave uncharacteristically deep scratches. These get knocked off early on, and the plate cuts more smoothly and consistently with fewer deep scratches. But this can be true of sandpaper, too. The difference is a few minutes of rubbing razor on sandpaper mellows it down, but it might take an hour or two of rubbing a big stainless chef knife to get the same effect on the DMT. YMMV and you might well never notice it anyway. You could indeed jump straight from DMT 1200 to 3u film and I guess some guys do yeah, but I don't think it is optimal to do so. Can still get the same edge, though. So don't let lack of intermediate grits stop you. Just be prepared to do some extra rubbing.What’s the difference between 1200 DMT and 1200 wet/dry sandpaper? If they are similar can I just jump to 3u film like Andy77?
That is certainly possible. Good catch.My lapping film from Thorlabs is Al Oxide at 3u and 1u while the 5u is Si Carbide. I wonder if that is what accounts for the slurry effect. Slash, perhaps your 5u was truly Al Oxide.