Just choosing the right sandpaper grit for your project. The smaller the grit number is, the coarser it is. The larger the grit number is, the finer it is. Grit Number: 60 80 100 120 150 180 240 320 400 600 800 1000 1200 1500 2000 2500 3000 4000 5000 7000 10000 Grit.
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