https://ebrasives.com/blogs/news/what-is-sandpaper-made-of-the-4-main-grits-used-today 2020-10-21T15:16:16+01:00 weekly https://cdn.shopify.com/s/files/1/0142/4864/0576/articles/truck.jpg?v=1603286509 What is sandpaper made of, the 4 main grits used today