Here’s a fact that will blow your mind: a single sheet of modern sandpaper has more abrasive particles than there are stars in the Milky Way. Okay, that’s an exaggeration—but it’s close. A standard 9x11 sheet of 80-grit paper packs about 10 million crushed-up rock shards.
And get this: the numbers on sandpaper—like 60, 120, 2000—aren’t just random lottery picks. They represent the size of the holes in a sieve that the particles are shaken through. The larger the number, the smaller the particles. So 2000-grit is basically fairy dust, while 40-grit is like the angry teenage cousin of a gravel driveway.
