My first impression of this was questionable at best, the packaging was terrible, it looked honest when opened, returned and then sent to the next person. The cellophane "wrap" it came in fell apart before it was taken down, meaning it had to sit on a shelf in the heat or the sun (maybe both) for a while. So I found that the sandpaper was also exposed to the elements, it was brittle, dried out and unusable. And I was right. I tried 3 different grits to see if it was just a bad piece but no, all 3 were torn, cracked and chipped on first use. I ordered this to use on glass for sanding between layers of resin. I can usually go through 3 or 4 (sometimes more) sheets. I couldn't even get through one. I don't like giving bad reviews but this was just terrible quality. I've included photos of what the sandpaper looked like after just one cup. The other after repeated grinding of all 7 cups I was working on. I would not recommend buying.