Why Sandpaper Matters for Your Paint ProjectAnd How to Choose the Right Sandpaper

A lot of DIY painters focus on paint color, brushes, rollers, and primer — but one of the most important parts of a good paint job happens before the paint ever goes on the wall.

That step is sanding.

At RPR Contractors, we know that a smooth, long-lasting finish starts with proper prep. Sandpaper may seem like a small detail, but it can make a huge difference in how your finished project looks and how well the paint holds up over time.

Why Sandpaper Matters

Sanding helps create the right surface for paint to bond to. If a wall, trim, or patched area is not properly sanded, even the best paint can end up looking rough, uneven, or unfinished.

Here’s why sanding is so important:

1. It smooths out patched areas

If you’ve repaired nail pops, dents, drywall seams, or holes, sanding helps feather those repairs into the surrounding surface. Without sanding, patched spots can stand out badly once the paint dries.

2. It removes rough spots and imperfections

Old drips, roller lint, brush marks, peeling edges, and debris can all show through new paint. Sanding knocks those down so the surface feels and looks more uniform.

3. It helps paint adhere better

Glossy or previously painted surfaces can be too slick for new paint to grab onto properly. A light sanding scuffs the surface just enough to improve adhesion.

4. It gives a more professional finish

A properly sanded surface helps the final coat lay down cleaner and smoother. This is especially important on trim, doors, cabinets, and repaired drywall.

5. It helps you catch flaws before painting

Sanding forces you to inspect the surface more closely. Many times, it reveals low spots, ridges, or rough repairs that should be fixed before paint goes on.

Not All Sandpaper Is the Same

One of the biggest mistakes DIYers make is using the wrong grit.

The word “grit” refers to how coarse or fine the sandpaper is. Lower numbers are rougher. Higher numbers are finer.

Choosing the right grit matters because you want to smooth the surface without damaging it.

Common Sandpaper Grits and What They’re Used For

60 to 80 grit

This is very coarse sandpaper. It removes material quickly.

Best for:

• Heavy paint buildup

• Rough wood shaping

• Very uneven surfaces

• Stripping down problem spots

Use with caution:This grit is usually too aggressive for normal wall prep or finish work. It can leave deep scratches if used in the wrong place.

100 to 120 grit

This is a good general-purpose grit for many prep jobs.

Best for:

• Smoothing drywall compound

• Sanding patched wall areas

• Knocking down rough paint edges

• Light prep before priming

For many interior painting projects, 120 grit is a very useful choice.

150 grit

This is one of the most practical grits for paint prep.

Best for:

• Smoothing filler and spackle

• Prepping previously painted walls

• Light sanding between coats in some situations

• General finish prep on trim and woodwork

If someone asks for one of the safest all-around grits for prep work, 150 grit is often a great answer.

180 to 220 grit

This is fine sandpaper.

Best for:

• Final smoothing before painting

• Sanding trim and doors

• Light sanding between coats

• Fine finish work

This grit is excellent when you want a smoother, more refined finish — especially on wood trim, cabinets, or previously painted surfaces.

What Sandpaper Should You Use for Common Paint Projects?

For patched drywall

Use 120 to 150 grit.This is usually enough to smooth the patch without gouging it.

For previously painted walls

Use 150 grit for light prep.If the wall has rough repairs or edges, start with 120 grit and finish with 150 grit.

For trim, baseboards, and doors

Use 150 to 220 grit depending on the condition of the surface.For smoother finish work, finer grit is usually better.

For glossy surfaces

Use 150 to 180 grit to lightly scuff the surface so primer or paint can bond better.

For sanding between coats

Use 180 to 220 grit very lightly.This is not for removing paint — just for smoothing dust nibs or minor imperfections.

A Few Important Sanding Tips

Don’t oversand

Too much sanding can damage drywall paper, round over trim details, or leave scratches that show through the paint.

Use a sanding block or pole sander when needed

Holding loose sandpaper in your hand can create uneven pressure. A sanding block gives better control, especially on flat surfaces.

Always remove dust before painting

After sanding, wipe the surface down or vacuum the dust. Paint should never go over sanding dust.

Wear a dust mask

Sanding creates fine dust, especially when working with drywall compound. Protect your lungs and your eyes.

Use good lighting

A wall can look fine until light hits it the wrong way. Side lighting helps you spot ridges, lines, and rough areas before painting.

Sanding Is One of the Biggest Differences Between DIY and Professional Results

A lot of people want a nice paint job, but rush through the prep. The truth is, the finish usually depends more on the prep than on the paint itself.

That’s why sanding matters.

When done correctly, sanding helps:

• improve adhesion

• reduce visible imperfections

• smooth out repairs

• create a cleaner final finish

• make your paint job last longer

Let RPR Contractors Help

At RPR Contractors, we know that good painting starts with solid prep work. That includes proper patching, sanding, surface repair, and attention to detail before the first coat even goes on.

If your walls, ceilings, trim, or repaired areas need professional prep and painting, we’d be happy to help.

RPR ContractorsReady to Refresh Your Home? Phone: 484-949-5258

Website: www.rprcontractors.netEmail: RPRContractors@aol.com