How do I match new wood to the colour of old wood?

Timber darkens with decades of light, oxidation and old finish, and it does so unevenly — the exposed faces more than the sheltered ones, the sapwood differently from the heartwood. That is a history you are trying to reproduce in an afternoon, so the only method that works is layering: several thin adjustments, each checked, rather than one hopeful application of a stain called antique pine.

What you'll need

• Offcuts of the new timber, sanded exactly as the repair will be
• Two or three stain colours that can be blended or layered
• The finish you intend to use, for the final check
• Tinted wax or a tinted finish, for the final adjustment
• Artists' pigments or a wood dye, for fine tuning

Step by step

1. Start with the right species and the right cut.No amount of colouring makes ash look like oak or a rotary-cut veneer look like quarter-sawn timber. Match the species first, then the cut and the grain direction, then worry about colour. On a repair to a visible piece, sourcing reclaimed timber of the same age is often easier than colour-matching new.
2. Clean the old surface before you judge its colour.What you are matching may be under decades of wax, polish and grime, and the actual timber colour beneath is different. Clean an area of the old wood as you intend to finish it, and match to that rather than to the dirt.
3. Sand the new timber consistently, and note the grit.Sanding grit changes how much stain is absorbed and therefore the final colour. Sand your test pieces and the repair to exactly the same final grit, and write it down, or your test will not predict the result.
4. Condition blotch-prone timber first.New pine, cherry, birch and maple absorb unevenly. A pre-stain conditioner or a thin coat of dewaxed shellac evens it out. Without this step the colour lands unpredictably and no amount of adjustment will fix it.
5. Build the colour in thin layers, testing at each stage.Apply a base stain lighter than your target — you can always add. Let it dry, look at it, and add a second thin application or a different colour on top to adjust the tone. Two or three light layers give a depth and variation that looks like old timber; one heavy application looks like stain.
6. Always judge with the finish on.Every finish changes the colour, and oil and polyurethane amber it substantially. Take your test piece all the way through to the finish before deciding, because a stain that looks right bare will look quite different under oil.
7. Adjust the last few percent with a tinted finish or wax.When the stain is close but not there, a tinted wax, a tinted oil or a coat of finish with a little pigment in it moves the tone without changing the wood. This is how professionals close the final gap, and it is reversible in a way that more stain is not.
8. Check in the light the piece actually lives in.A match made under a workshop fluorescent will not necessarily hold under a warm lamp in the evening or by a north window. Take the sample to the piece, and look at it at two or three times of day before committing.

Tips

• Deliberately aim a shade lighter than the old wood. New timber continues to darken, and a repair that starts slightly light will blend in over a year, while one that starts too dark stays wrong forever.
• Where a perfect match is impossible, a deliberate contrast often reads better than a near-miss. A repair that is honestly different looks intentional; one that is nearly right looks like a mistake.
• Keep every test piece, labelled with what was on it and in what order. The next repair to the same piece will be far quicker.

Common mistakes

• Buying one stain called by the name of the old wood — Stain names describe the tin, not your timber. The same stain on two species gives two colours, and old wood has a depth no single application reproduces.
• Judging colour on bare wood — The finish changes it substantially, and oil-based finishes amber it further over time. Always take a test through to the finish.
• Going too dark on the first attempt — Stain only goes darker, and the only way back is sanding it out. Start light and build.

If it doesn't work

Questions people ask