Understanding Sandpaper for Wood: A Comprehensive Guide

Sandpaper has gotten complicated with all the grit ratings, abrasive types, and backing materials flying around. As someone who has sanded more board feet of lumber than I care to count, I learned everything there is to know about choosing and using sandpaper for woodworking. Today, I will share it all with you.

I’ll tell you something most articles won’t — sanding is the part of woodworking nobody loves but everybody needs to get right. I’ve rushed through sanding plenty of times over the years, and every single time, the finish told on me. A bad sanding job shows through every coat of poly, stain, or oil you apply. There’s no hiding it. So yeah, understanding your sandpaper actually matters.

What Is Sandpaper?

At its most basic, sandpaper is abrasive grit bonded to a backing material. That’s it. But the type of grit, how it’s bonded, and what it’s stuck to makes a huge difference in how it performs. The three abrasive types you’ll encounter most often in woodworking are aluminum oxide, silicon carbide, and garnet. Each one behaves differently.

The backing material matters too. Paper, cloth, foam, fiberglass — they all flex and tear differently. I’ve gone through way too many sheets of cheap paper-backed sandpaper that ripped on me mid-stroke to not care about this stuff.

Grit Size and Why It Matters More Than You Think

Grit numbers tell you how coarse or fine the sandpaper is. Lower number equals bigger, meaner abrasive particles. Higher number equals finer particles for smoother finishes. Here’s the breakdown I work with in my shop:

• 40-60 grit: This is the aggressive stuff. I use it for stripping old finishes, flattening glue-ups, or shaping rough stock. It removes material fast but leaves deep scratches. Don’t start here unless you actually need to.
• 80-120 grit: The workhorse range. This is where I do most of my initial sanding on furniture projects. 80 grit knocks down saw marks and planer ridges. 120 grit smooths things out enough for the next step.
• 150-180 grit: Final sanding before finish for most projects. After 180 grit, the surface feels smooth under your fingertips and accepts stain evenly. For paint-grade work, you can often stop here.
• 220 and above: Fine sanding territory. I go to 220 before applying oil finishes on walnut or cherry. Between coats of poly, I’ll hit the surface with 320 or higher. Some folks go to 400+ for a glass-smooth feel. I usually don’t need to go that far on furniture.

Types of Abrasives — What’s Actually on That Paper

Probably should have led with this section, honestly. The abrasive type determines how the sandpaper cuts and how long it lasts.

• Aluminum Oxide: This is my go-to for 90% of sanding tasks. It’s tough, it self-sharpens as it breaks down (the particles fracture and create new cutting edges), and it works beautifully with power sanders. If you’re only going to buy one type, make it aluminum oxide.
• Silicon Carbide: Sharper than aluminum oxide but wears out faster. I use it almost exclusively for sanding between finish coats. The black wet/dry silicon carbide paper in 400 grit is a shop staple for me. Wet sand a coat of poly with it and the smoothness is incredible.
• Garnet: The old-school choice. Garnet is a natural mineral and it cuts softer than the synthetic options. That actually makes it great for hand sanding before staining — it burnishes the wood fibers slightly, which helps stain absorb more evenly. The tradeoff is it wears out quick. I keep some around for final hand sanding on special projects.
• Emery: This one is really more for metalwork. I’ve got some in my shop for deburring hardware, but I don’t use it on wood.

Backing Material

The stuff the grit is glued to affects how the sandpaper handles, flexes, and holds up.

• Paper Backing: Cheapest and most common. Fine for hand sanding and lighter power sanding. Tears easier than cloth, though. The weight ratings (A through F, with A being lightest) tell you how heavy-duty the paper is. C and D weight are what you want for most shop work.
• Cloth Backing: Way more durable and flexible. I use cloth-backed belts on my belt sander and cloth-backed strips for hand work on curves. Costs more, lasts way longer. Worth it for anything that sees heavy use.
• Foam Backing: These sanding sponges are lifesavers for curved surfaces, molding profiles, and hard-to-reach spots. I keep a few different grits in my bench drawer at all times. They conform to shapes that flat sandpaper just can’t handle.
• Fiberglass/Mesh: Newer on the scene. Mesh-backed sanding discs resist clogging because dust passes through the mesh instead of building up on the surface. I’ve been using them more on my random orbit sander lately and they do stay effective longer, especially on resinous woods like pine.

Sandpaper Forms for Different Jobs

Sandpaper comes in all shapes and sizes, and matching the form to your tool or technique matters:

• Sheets: The classic 9×11 sheet you tear or cut to size. I wrap these around a cork sanding block for flat surfaces. You can also fold them in thirds for hand sanding edges and small parts.
• Discs: Hook-and-loop or PSA (peel-and-stick) discs for random orbit sanders. I buy 5-inch hook-and-loop discs in bulk — 80, 120, 180, and 220 grit. That covers 95% of my sanding work.
• Belts: For belt sanders. Great for aggressive stock removal on flat surfaces. I use a 4×24 belt sander for flattening tabletops and stripping old finishes. Just be careful — belt sanders eat wood fast if you’re not paying attention.
• Sponges: Flexible foam blocks coated with abrasive. Perfect for hand sanding chair legs, molding profiles, and anything with curves. I grab these for every furniture project.

How to Sand Wood the Right Way

Here’s my process, learned through years of trial and error. Always sand with the grain. Always. Sanding across the grain leaves scratches that show up like neon signs under a finish. I learned this on my very first cherry table and had to redo the entire top.

Start with the coarsest grit you actually need — not the coarsest you own. If the surface just has light milling marks, start at 120. If it’s rough-sawn, start at 80. Work through the grits sequentially: 80, 120, 150, 180, 220. Don’t skip grits. Jumping from 80 straight to 220 means the fine paper is trying to remove deep scratches left by the coarse paper, and it takes forever.

Apply even pressure and let the sandpaper do the work. Pressing harder doesn’t sand faster — it just wears out your paper and creates uneven spots. That’s what makes good sandpaper endearing to us woodworkers who sand a lot — quality paper that cuts consistently with light pressure is worth every extra penny.

Storing and Maintaining Your Sandpaper

Humidity is the enemy. I’ve pulled sandpaper out of a drawer in August and found it curled up and gummy from moisture. Now I store mine in a sealed plastic bin with a silica gel packet. Sounds overkill, but it works.

Clean clogged sandpaper with a rubber cleaning stick (basically a big eraser). Run it across the surface and it pulls out embedded dust and extends the paper’s life significantly. I’ve doubled the lifespan of sanding belts this way. Store sheets flat or loosely rolled — creased sandpaper doesn’t sand flat.

Environmental Considerations

Used sandpaper picks up whatever was on the wood — paint, stain, finishes, sometimes lead on older pieces. I toss mine in the regular trash, but if you’ve been sanding anything with lead paint, that’s hazardous waste and needs to be handled properly. Just something to be aware of.

On the production side, aluminum oxide and silicon carbide are manufactured materials, but they’re not particularly toxic or scarce. Paper backings come from managed forests. Not the most environmentally impactful product in your shop by a long shot.

Specialized Techniques I Actually Use

Wet sanding is a game-changer for fine finishes. I wet sand between coats of polyurethane with 400-grit silicon carbide paper and a little soapy water. The surface comes out impossibly smooth. On the final coat, I’ll sometimes go to 600 or even 800 grit wet, then buff with steel wool. The result looks like glass.

Block sanding is non-negotiable for flat surfaces. Your hand has too much give — it’ll sand hollows into a flat panel before you realize what’s happening. A rigid sanding block distributes pressure evenly. I use a cork block for most work and a hard rubber block for really flat surfaces like tabletops.

Mistakes I’ve Made So You Don’t Have To

Starting too fine. I used to think 220 grit was a safe starting point for everything. It’s not. On rough stock, 220 barely does anything — you’re just wasting time and paper. Match your starting grit to the surface condition.

Skipping grits. Went from 80 to 180 once because I was impatient. The finish showed every single 80-grit scratch through the stain. Had to strip and start over. That afternoon of “saved time” cost me an entire weekend.

Sanding cross-grain. Even a few strokes across the grain leave marks that become glaringly obvious under stain, especially on open-grained woods like oak. Always finish with strokes running parallel to the grain.

FAQ: Sandpaper for Wood

• What is the best sandpaper for wood? Aluminum oxide for most tasks. Start with whatever grit matches your surface condition (usually 80-120) and work up to 180-220 for a finish-ready surface.
• Can sandpaper be reused? Absolutely. Clean it with a rubber stick, and it’ll cut like new for a while. Replace it when it stops cutting effectively or the grit starts falling off.
• What sandpaper works for varnish removal? Start at 80 grit to break through the finish, then move to 120 and 150 to smooth everything down. Consider a chemical stripper first for thick finishes — it’ll save your arms and your sandpaper budget.
• Is hand sanding inferior to machine sanding? Not at all. I hand sand every project for the final pass, even after using a power sander. Hand sanding gives you feel and control that machines can’t match. For curved surfaces and details, hand sanding is actually superior. I use power sanders for the heavy lifting and hand sand for the finesse work.