I need to modify my previous comment. I think the coarser grit Chinese laps are awesome preformers and the 600 grit is great for fine cutting. After the 600 grit, I switch to a worn 1200 Dyna lap for prepolish. I think the finer grit Chinese laps are too aggressive for prepolishing. That may change after I get some more wear on them. Might have to cut some sapphires to wear them in a bit more.