When you’re laboring away on a woodworking project you’ll likely need multiple types of sandpaper, from a course grit for rough surfaces to a finer grit as you finish. But sandpaper is available in a wide spectrum of grit, so how do you know which to buy? Here are the only three types you’ll really need.

Steve Ramsey of Woodworking for Mere Mortals simplifies it down into the three basic grades of grit that you’ll need for the vast majority of your projects: 120, 80, and 220.

120 grit is his primary workhorse for the majority of work. The lower the grit the rougher the paper, so Steve recommends you have 80 grit paper on hand for more aggressive shaping. And as you’d expect, the finer 220 grit is for finishing and surfacing a project. Watch his video for more sandpaper fundamentals and tips.

The Only 3 Sandpapers You Really Need via Popular Mechanics