The Rule of Thumb Guide to the Right Sandpaper Grit for Your Project

Kenneth Wilson

You’re getting ready to start a new project. Whether you’re working with wood or patching drywall, chances are you’ve noticed that you’ll need to do some sanding. For experienced do it yourselfers, you probably know there are many different grits of sandpaper. However, for people just getting into home improvement projects, you may be surprised at all the sandpaper options in your local home improvement store.

However, regardless of who you are, choosing the right sandpaper grit for your project is critical for seeing good results. Fortunately, making this choice is quite straightforward. Let’s take a look at what differentiates types of sandpaper and how to ensure you’re using the right grit.

What is Meant by Sandpaper Grit?


Grit is a value by which the abrasive material on sandpaper is measured. This measure is associated with a number. As a general rule, as the grit number increases, the grains get smaller, providing a more fine grit. Grit is typically measured by something called the CAMI scale although European product may use a scale known as FEPA.

Sandpaper is made with machines that ultimately serve as sifters. This means that only particles of a certain size make it through and onto the surface of the sand paper. This is how manufacturers ensure that a consistent grit is seen across an entire sheet of sandpaper.

Another important word to know is grain. Grain refers to a more broad type of sandpaper comprising a range of grits. For example, extra fine sandpaper is a grain category that comprises the largest range of grits, those from 240 to 400.

Below are the types of grains and their corresponding grit ranges.

Grain

Grit

Coarse

60 – 80

Medium

100 – 150

Fine

180 – 220

Extra Fine

240 - 400

Why Is Choosing the Right Grit Important?


If you haven’t worked with sandpaper for long, you might assume that sandpaper is sandpaper. After all, it all works to sand down a surface, right? Actually, selecting the right sandpaper grit for your project is very important. The wrong grit can leave you frustrated or with a quality of finished product that you simply are not happy with.

Coarse sandpaper is great for easily removing wood and other materials. It works fast with less effort. However, it also leaves very deep scratches. By comparison, fine sandpaper removes only a tiny amount of material, making it easy to get a smooth finish on the surface.

If you are sanding with too fine of a sandpaper grit, you will find it more difficult to finish the job. You also may over-sand which can lead to producing a shiny surface that has trouble absorbing stains and finishes, which can alter the look of the finished product.

Thus, the general goal when working with sandpaper is to begin with the highest grit that will meet your needs then move up to finer grits (higher numbers) as you get closer to the finished product.

What Grit Should I Use for My Project? 


Now that we have a good understanding of what is meant by grit and grain as well as the problems with choosing the wrong one, let’s take a look at the grit you should choose for your particular project.

  • Drywall - For drywall projects, you will want to use a medium grain. In fact, it is ideal to use a grit from 120 to 150. Many people find success using 120 followed by a final sand with a 150 grit sandpaper. Any grit coarser than 100 should never be used on drywall as the gashes they make in joint compound will be able to be seen through the paint. Additionally, anything finer than 220 will be frustrating as it will clog easily during sanding. Thus, 120 to 150 is the place to go.
  • Wood - The most frequently used sandpaper grain for most wood projects is medium. It is hard to go wrong with this unless you are working on fine details. For this reason, medium grain sandpaper is great to have on hand in general. Second or third sanding treatments should be done with fine grits of up to 220. If you are wanting to take off paint or round edges, using coarse grits from 60 to 80 will work. Otherwise, this will be too rough and you’ll want to start with medium. For wood projects that will be painted, doing a final sanding with 150 grit is advised. (Related: How To Reface Kitchen Cabinets? We Break It Down)
  • Furniture - A common project for many people involves restoring old furniture. When working with furniture and wood projects that have very fine details, even medium sandpaper will prove too coarse. Thus, you’ll want to focus on fine or even extra fine grains for these projects. However, if you are applying a coat of stain to bare wood, do not use anything more fine than 220.
  • Between Coats of Paint - If you need to sand between applying coats of paint or varnish, you will want to utilize extra fine sandpaper. Typical grits used include 240, 320, and 400. These are extremely fine and best for these types of jobs.

Final Thoughts


Whether sanding down an old countertop, working with wood, or putting up drywall, choosing the right sandpaper grit for your project will ensure that the final results look great. Fortunately, selecting the right sandpaper grit is not rocket science.

Understanding the performance of coarser versus finer grits and the types of projects they work best on is key. Remember, coarse sandpaper is only utilized for the toughest of jobs while medium is often good for a first sanding for all except the finest detailed projects. With this knowledge, you’re assured to have an easier time with your next project.

Kenneth Wilson
November 10, 2021
Contractor Tips

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

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