Not all grit sizes are created equal, and as with most things, you get what you pay for with sandpaper. The grit number indicates the size of the particles used to abrade the surface, but the more consistent the size, the fewer "high points" there will be.

Sandpaper "scratches" the work surface to reduce irregularities and high spots. If all the scratches are the same depth and width, the result looks smootherthan before. A few particles that are larger than the rest will scratch more deeply into the surface leaving marks. You might not even see these marks, but you can bet that staining the part will highlight every one of them.

Separating and sorting the abrasive particles when making sandpaper requires care, and that costs money. Cheap brands are likely to cause frustration and rework, so be careful about the sanding supplies you choose.

But we all find ourselves under the gun and sometimes the only sandpaper available is an unknown quality. Here's a tip: Run your sander lightly on a clean section of concrete floor or wall. This "pre-wear" will tend to knock off the high points first, leaving a more level surface for sanding. Try it, it works! Check out the different types of sandpaper sheets we carry! Our other blog about types of sandpaper will help you decide between silicon carbide sandpaper and aluminum oxide sandpaper! We can also provide you with custom sandpaper sheets, discs, rolls, and more, with various grits, widths, etc.