How to Choose Sandpaper Grit

Understanding Sandpaper Grit Numbers

Sandpaper grit refers to the size of the abrasive particles bonded to the backing material. The number corresponds to how many particles fit through a square inch of mesh screen — so a lower number means larger, more aggressive particles that remove material quickly, while a higher number means finer particles that produce smoother surfaces.

In automotive refinish, selecting the correct grit sequence is critical. Starting too fine wastes hours of labor because you are not removing material efficiently. Starting too coarse creates deep scratches that telegraph through primer, sealer, and even clearcoat — showing up as visible lines under direct light. The goal is always to use the coarsest grit that the next step in your process can refine out.

The Scratch Pattern Rule

Every abrasive grit leaves a characteristic scratch pattern. The next grit in your sequence must be fine enough to completely remove the previous scratch pattern without adding undue depth. As a rule of thumb, never skip more than one grit step. For example, jumping from 80 grit to 320 grit leaves behind 80-grit scratch valleys that 320 cannot fully level — those scratches will ghost through your finish. The correct sequence would be 80 → 150 → 220 → 320.

Complete Automotive Refinish Grit Chart

Grit Range	Classification	Application	Recommended Products
36–60	Extra Coarse	Stripping old finishes, heavy rust removal, initial shaping of body filler	PSA DA Discs, Sanding Rolls
80–100	Coarse	Rough shaping body filler, aggressive featheredging, grinding welds	PSA DA Discs, Rolls
120–180	Medium	Final filler shaping, featheredge blending, initial primer prep, E-coat scuffing	Hook & Loop DA Discs
220–320	Fine	Primer leveling, guide coat sanding, surface refinement before sealer	Hook & Loop DA Discs, Foam DA Discs
400–600	Very Fine	Final primer sand, pre-paint preparation, wet sanding between coats	Foam DA Discs, Wet/Dry Sheets
800–1000	Extra Fine	Wet sanding clearcoat, removing orange peel, color sanding	Wet/Dry Sheets
1200–1500	Super Fine	Final color sanding before compounding, defect removal in clearcoat	Wet/Dry Sheets
2000–3000	Ultra Fine	Final wet sand before polish, achieving mirror-like clarity in clearcoat	Wet/Dry Sheets

Recommended Grit Sequences by Repair Type

Below are the exact grit progressions used by top shops. Each sequence is designed so that every successive grit completely removes the scratch pattern left by the previous one.

Full Panel Repaint (Bare Metal to Clear)

This is the most aggressive sequence, used when stripping a panel down to bare metal or taking a panel through the complete refinish cycle.

• Step 1 — Strip / Featheredge (80 grit): Remove old finish down to bare metal or featheredge existing paint. Use 80-grit PSA DA discs on a dual-action sander for fast material removal.
• Step 2 — Shape Filler (150 grit): After applying body filler, block-sand with 150-grit sanding rolls or a long board to achieve the correct panel contour. Check your work with a guide coat.
• Step 3 — Refine Filler (220 grit): Switch to 220-grit Hook & Loop DA discs to smooth the filler surface and eliminate all 150-grit scratches. This is the last step before primer.
• Step 4 — Level Primer (320 grit): Once primer is applied and cured, block-sand with 320 grit using a foam DA pad. Apply guide coat between passes to confirm you have leveled all imperfections.
• Step 5 — Pre-Paint Sand (400–500 grit): Final sand before sealer or basecoat. Use 400 or 500-grit foam discs for a smooth, paint-ready surface. Blow off with compressed air and tack wipe before painting.

Spot Repair / Blend

Spot repairs target a small area — a door ding, a rock chip, or a localized scratch. You repair the damage zone and blend the new paint into the surrounding finish.

• Step 1 — Featheredge (150 grit): Sand the damaged area to create a smooth transition between the old paint and bare substrate. Use 150-grit Hook & Loop discs on a 3" or 5" DA sander.
• Step 2 — Prime and Sand (220–320 grit): Spot-prime the repair area. After curing, block-sand with 220, then 320 grit. The surrounding panels only need a light scuff with scuff pads (gray or gold) to accept paint.
• Step 3 — Final Prep (400–500 grit): Sand the primed area with 400–500 grit. Scuff the blend zone with gold scuff pads. Tack wipe everything before paint.

Clearcoat Color Sand and Buff

After painting, this sequence removes orange peel, dust nibs, and minor runs to achieve a factory-smooth or show-car-level finish.

• Step 1 — Initial Cut (1000 grit): Wet-sand the clearcoat with 1000-grit wet/dry sheets using a hard rubber sanding block. Keep the surface wet and use light, even pressure. This levels the orange peel texture.
• Step 2 — Refine (1500 grit): Switch to 1500-grit sheets to refine the 1000-grit scratch pattern. Continue wet sanding until the surface has a uniform, hazy appearance with no visible deep scratches.
• Step 3 — Final Sand (2000–3000 grit): Wet-sand with 2000 or 3000 grit. This creates a micro-fine scratch pattern that compounds can easily remove. The surface should look uniformly foggy with no visible grain.
• Step 4 — Compound: Machine-compound with a cutting pad to restore clarity. Wipe down and inspect under direct light for any remaining sanding marks.
• Step 5 — Polish: Finish with a fine polish and foam pad to achieve full gloss and depth.

E-Coat / OEM Finish Scuff (New Panel Prep)

New replacement panels arrive with an electrocoat (E-coat) layer. You must scuff the E-coat to promote adhesion — but not cut through it.

• Scuff the E-coat surface with gray scuff pads or 320-grit foam DA discs.
• Apply sealer directly over the scuffed E-coat, followed by basecoat and clearcoat.
• Never use anything coarser than 320 on E-coat — cutting through the E-coat removes corrosion protection and will require repriming.

PSA vs Hook & Loop vs Film-Backed

The backing type affects how the disc attaches to the sander, how it cuts, and how long it lasts. Choosing the right backing for the job is just as important as choosing the right grit.

PSA (Pressure Sensitive Adhesive)

• Sticks directly to the sander pad with a peel-off adhesive backing
• Aggressive cut — the disc cannot flex away from the surface, so it removes material faster
• Ideal for heavy removal work: stripping, filler shaping, featheredging
• Cannot be repositioned once applied — one use per disc
• Best for: 36–180 grit heavy-duty work
• Shop PSA DA Sanding Discs →

Hook & Loop (Velcro-style)

• Attaches and detaches quickly from a hook & loop pad — swap discs in seconds
• Slightly more cushioned cut than PSA, which reduces accidental dig-throughs
• Best for multi-grit sanding sequences where you progress through several grits on one panel
• Discs can be removed and reused if they still have life
• Best for: 120–600 grit general sanding and primer work
• Shop Hook & Loop DA Discs →

Film-Backed

• Ultra-smooth polyester film backing instead of paper — extremely consistent scratch pattern
• Tear-resistant and waterproof — outlasts paper-backed discs 2-3x
• Produces finer, more uniform scratches at any given grit than paper-backed equivalents
• Preferred for final sanding before paint where scratch uniformity matters most
• Best for: 320–800 grit final prep and primer sanding
• Shop Foam & Film DA Discs →

Top Product Picks by Application

Pro Tips for Better Sanding Results

• Never skip more than one grit step. Jumping from 80 to 320 leaves deep scratches that show through the finish. Follow the progression: 80 → 150 → 220 → 320.
• Always use guide coat. A light dusting of contrasting guide coat between grits reveals low spots, pinholes, and remaining scratches. If guide coat remains in an area after sanding, that area is low — do not sand harder, add more filler or primer instead.
• Match sanding pattern to the grit. Use cross-hatch (X-pattern) for rough grits to ensure even material removal. Switch to straight-line sanding for 320 grit and finer to minimize visible scratch patterns under paint.
• Replace discs when they stop cutting. A worn disc generates heat without removing material. That heat softens filler and primer, causing loading and uneven surfaces. Fresh abrasive is always more efficient than pressing harder with a dull disc.
• Control your sanding speed. Keep DA sander speed at 50-75% for fine grits (320+). Running too fast generates heat and can burn through primer or clearcoat. Slow, steady passes produce better results.
• Wet sand correctly. When wet sanding (800+ grit), use a rubber sanding block for flat panels and a flexible pad for curves. Keep the surface flooded with clean water. Squeegee frequently to check your progress — you want a uniform, hazy surface with no shiny low spots.
• Block sand whenever possible. Hand sanding without a block follows body contours and can create waves. A rigid sanding block ensures a flat, true surface. Use a long board for large, flat panels and a hand block for smaller areas.
• Clean between grits. Blow off the panel with compressed air and wipe with a tack cloth before switching to the next grit. Loose particles from a coarser grit will contaminate the finer grit and create deeper-than-expected scratches.