Sandpaper grit is a number that tells you how coarse the paper is: low numbers cut fast and leave scratches, high numbers cut slowly and leave a smooth surface. Most wood projects move through three or four grits in order, never skipping more than one step. This guide shows what each range is for.
What the numbers mean
The number relates to how many abrasive particles fit in a given area. A larger number means finer particles. Papers are usually grouped by range.
- Coarse (around 40 to 60): removes material, old finish and deep marks fast.
- Medium (around 80 to 120): levels surfaces and removes scratches left by coarse paper.
- Fine (around 150 to 220): smooths wood for most finishes.
- Very fine (240 and above): polishes between coats of finish and softens edges.
A simple grit progression
| Stage | Typical grit | Purpose |
|---|---|---|
| Stripping or shaping | 40 to 80 | Remove old coatings, flatten rough boards |
| Leveling | 100 to 120 | Erase marks from the first stage |
| Smoothing | 150 to 180 | Prepare bare wood for stain or oil |
| Final prep | 220 | Last pass before the first coat of finish |
| Between coats | 320 or finer | Knock down dust nibs on the dried finish |
How to sand step by step
- Wipe the surface and check for nails or screws that could tear the paper.
- Begin with the coarsest grit that is really needed, not the coarsest you own.
- Sand with the grain, using even pressure and overlapping strokes.
- Remove dust before changing to the next grit so you do not drag loose particles around.
- Move up one grit at a time until the surface feels smooth and looks even in raking light.
Other things worth knowing
Hardwoods usually look best finished at around 180 to 220, while softwoods can blotch if sanded too fine before staining. Hand sanding with a block keeps flat areas flat. Power sanders save time but can round edges if tilted. Wear a dust mask and eye protection, and use dust collection if your sander supports it. Follow the maker’s manual for your tool.
Paper type matters as well as grit. Aluminum oxide is a common all-round choice for wood, silicon carbide suits finishes and metal, and open-coat papers clog less on resinous wood. Replace paper as soon as it looks glazed, because worn paper polishes instead of cutting.
Abrasive Materials Compared
Grit tells you how coarse the paper is, but the abrasive material decides how it behaves. Aluminum oxide is a common all-round choice for wood and paint because it is tough and long-lasting. Silicon carbide is sharp and often used on finishes, plastics and metal, and is common in wet-or-dry papers. Garnet is a natural abrasive that many woodworkers like for hand sanding bare wood, because it wears down and leaves a fine finish, though it tends to wear out faster. Ceramic abrasives are designed for heavy removal and tough materials, usually on power sander discs and belts.
Check the pack description for what the manufacturer says the paper is for. A paper meant for drywall will not suit hardwood furniture, and a paper meant for metal may not be ideal for fine wood. If you are unsure, begin with an aluminum oxide paper for general work, and add specialized papers when you have a clear need.
The backing also matters. Paper backing is flexible and suited to hand sanding and detail work. Cloth backing is stronger and used on belts and for curved shapes. Foam-backed pads conform to contours. The listing or packaging should explain which sanders and tasks the product is made for.
Choosing by Project Type
Different projects call for different starting points and finishing grits.
- Stripping an old finish: start coarse, but consider a chemical stripper or scraper first so you do not wear out paper. Take care not to gouge the wood.
- Flattening a rough board: a medium-coarse grit levels quickly. Move to finer grits once the surface is flat.
- Furniture refinishing: work through the full progression and finish in the fine range before staining or oiling.
- Painted trim and walls: a fine or very fine paper scuffs glossy paint for better adhesion and smooths filler.
- Between coats of varnish: very fine paper removes dust nibs. Follow the finish maker’s instructions.
- Metal and rust: use papers made for metal, and wear suitable protection.
Always begin in a hidden spot if you are unsure how the wood or finish will react. Veneered surfaces and thin plywood faces can sand through quickly, so use light pressure and finer grits. Check the manufacturer’s advice for composite materials, plastics and specialty finishes.
Hand Sanding Versus Power Sanders
Hand sanding is slow but controlled. It suits small areas, curves, delicate edges and final smoothing. Wrapping paper around a block helps keep flat areas flat and prevents finger grooves. For curves, use a flexible pad or a piece of dowel.
Power sanders save effort on large surfaces. A random orbital sander is popular for general work because its motion helps avoid obvious scratch patterns. A detail sander reaches corners. A belt sander removes lots of material quickly, but can gouge wood if used carelessly. A sheet sander uses a quarter or half sheet of paper and suits flat work.
Match the paper to the tool. Discs and belts come in specific sizes and attachment types, such as hook-and-loop or adhesive, so check the sander’s manual. Keep the sander flat on the surface and moving, and don’t press hard; let the abrasive do the work. Keep the cord clear of the path. Use dust collection if the tool supports it, and wear eye protection, hearing protection and a dust mask suited to the material. Finish with hand sanding along the grain to remove swirl marks.
Spotting and Fixing Sanding Problems
Several problems show up after you apply a finish, so check the surface before then. Wipe it with a damp cloth or mineral spirits where the finish maker allows, or use a raking light, to reveal scratches, glue spots and dust. If you see swirls or cross-grain marks, go back one grit and sand with the grain.
Uneven color after staining is often caused by uneven sanding, leftover glue or blotchy woods. Resanding the area and testing the stain on a scrap piece help. Some woods take stain unevenly, and a conditioner may be recommended by the stain maker.
Burn marks or glazed paper appear when you press too hard or keep using a worn sheet. Replace the paper and lighten your pressure. Rounded edges and lost detail come from too much sanding in one spot or tilting a power sander. Dust left on the surface can scratch it when you move to a finer grit, so vacuum or wipe the dust between grits.
If you sand through a veneer, there may be no easy repair, so stop earlier on thin surfaces. Take your time, check progress often, and stop when the surface looks and feels right.
Storing and Extending the Life of Sandpaper
Sandpaper wears out as the abrasive dulls or clogs, but good habits make it last. Keep it flat and dry, since damp conditions and folding damage the backing and the abrasive. Store sheets in a folder, drawer or labeled box sorted by grit, so you can find the right one and avoid mixing coarse grit into finer stock.
Use a rubber or cork block to spread pressure evenly and prolong the life of the paper. Tap or brush the sheet to clear dust, and consider a cleaning stick or eraser-like block for sanding discs where the maker recommends it. Don’t keep using a clogged sheet, as it burnishes the surface instead of cutting.
Know when to replace it. If the paper slides without cutting, shows shiny patches, or the surface is not improving, a new sheet will save time. Using a worn sheet can heat the wood and cause marks. Dispose of used paper and dust according to local guidance, and be careful with rags and dust that have been in contact with oils or finishes, following the label instructions. Buying quality sheets in quantities you will really use is better than a large pack that sits unused.
FAQ
Can I skip grits to save time?
Skipping one step is sometimes fine, but large jumps leave deep scratches that the finer paper cannot remove.
What grit should I use before staining?
Many woodworkers finish at 180 or 220 for stain. Check the finish label and the wood species for guidance.
What is the difference between wet-or-dry and regular sandpaper?
Wet-or-dry papers use a waterproof backing and can be used with water to reduce dust and clogging. They are common for finishes and metal. Check the pack for suitable uses.
Do higher grits always give a better result?
Not always. Very fine grits can burnish wood and reduce stain absorption. Match the final grit to the finish.
How do I know when to change grit?
Move on when the scratches from the previous grit are gone and the surface looks uniform. Check in raking light.
Can I reuse sandpaper?
You can use it until it is clogged or worn. Clean it gently to extend its life, but replace it when it stops cutting.
Should I sand between coats of paint?
Many finish makers suggest a light scuff sand with fine paper for a smooth result. Follow the instructions on your product.
Is it okay to sand with the grain only?
Yes, that is the usual advice for bare wood because cross-grain scratches show. Some stripping tasks use other directions, but finish with the grain.
Do I need a mask when sanding?
Yes, a dust mask suited to the material is recommended, along with eye protection. Work with ventilation and dust collection where possible.
The Short Version
Low numbers cut, high numbers smooth. Work upward through the grits in order, sand with the grain and clear dust at each stage.