Sandpaper Grit Picker: Your Exact Sanding Sequence
Tell the picker what you’re starting with and what finish you’re heading for, and it returns the exact grit sequence — every step, in order, with the reason for each. It applies the two rules that matter (never skip more than one grit step; start as fine as the job allows) so you don’t have to re-derive them at the hardware store.
What the picker does
Every sanding question is really the same question: which grits, in which order, and where do I stop? The answer depends on just two things — how rough the surface is now, and what’s going on top of it when you’re done. The picker encodes the standard ladder (each grit erases the scratches of the one before it) and the stopping rules (paint hides scratches that stain amplifies; bare wood almost never needs anything past 220), and hands you the sequence.
It exists because the two classic mistakes run in opposite directions: skipping grits (the 220 never reaches the bottom of the 80-grit scratches, and stain finds them), and starting too coarse (every pass at 60 removes wood you can’t put back — if 120 will do the job, 80 was a mistake).
The rules it applies (so you can check its work)
- Never skip more than one step in the standard sequence (80 → 120 → 180 is fine; 80 → 220 is not).
- Stop at 180 before paint — primer and paint fill and hide finer scratch patterns.
- Stop at 220 before stain or clear finish — past that you’re burnishing, which blocks absorption.
- Blotch-prone woods stop at 180 before stain — pine, maple, birch, and cherry stain more evenly with a slightly opener surface.
- A sound existing finish gets scuffed, not stripped — repainting furniture usually needs one pass, not a ladder. That whole philosophy is covered in how to sand furniture without stripping.
- Failed finishes come off coarse — the full stripping walkthrough (including when to reach for a chemical stripper or a heat gun instead) is in the paint-removal grit guide.
- Floors are their own ladder — drum sanders and 36 grit play by different rules, covered in the hardwood floor grit sequence.
Worked example
Say you’re finishing a bookshelf built from store-bought pine boards, headed for stain. Planed boards start at 120 (they left the mill smoother than 80 deserves). Normally the ladder would run 120 → 180 → 220 — but pine is blotch-prone, so the picker stops you at 180 and suggests a pre-stain conditioner. Three grits become two, and the stain comes out more even than the “sand finer!” instinct would have produced.
Same shelf headed for paint instead: 120 → 180 and you’re done either way — paint doesn’t care about the difference past 180.
Who this is for
Anyone standing in the sandpaper aisle buying grits by vibes. Run the job through the picker first and you’ll buy two or three grits instead of five, and skip the ones that would have wasted an afternoon. Pair it with a random orbital sander for the coarse steps — and if you’re polishing an actual finish film past 400, that’s wet sanding, a different technique with its own guide. Sheet quality varies more than people think, too; we compared the majors in the sandpaper brands guide.
Frequently Asked Questions
What grit sequence should I use on bare wood?
For rough or weathered wood: 80 → 120 → 180, adding 220 if the wood is getting stain or a clear finish. For planed, store-bought boards, start at 120 instead — they don’t need 80. Stop at 180 if you’re painting.
Can I skip grits to save time?
You can skip at most one step in the standard sequence, and only on wood in good shape. Skip more and the fine grit polishes the tops of the coarse scratches without reaching the bottoms — invisible until stain pools dark in them. Counterintuitively, not skipping is faster: each grit removes the previous one’s scratches in a couple of passes.
What’s the best single grit if I only buy one?
120 — it shapes, smooths, and scuffs acceptably. The moment you own two, make it 80 and 220 and you can walk the whole ladder for most furniture work.
Does the picker handle CAMI vs FEPA (P-grit) numbers?
The sequences use American CAMI numbers, but below 220 the two systems track closely enough to treat P120 as 120. Above 220 they diverge (P400 ≈ 320 CAMI) — check the prefix before buying between-coats paper.