Note 02
Reading surface wear
A mark in a finish is not automatically a mark in the wood. The useful skill is to say which layer failed, and to photograph it in a way another person can read.
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A field guide to common marks
These are patterns, not a diagnosis. Two marks can sit on top of each other. Compare a hidden area — inside a door, under a lamp base — with the marked face before you decide the colour has “always been like that”.
| What you see | Often sits in | Photograph |
|---|---|---|
| A pale or white ring, smooth to the finger | Moisture caught in a film finish. The wood underneath may still be sound. | Raking light from one side, plus a wider shot so the ring’s size is clear. |
| A dark ring or a black tide line | Water that reached the wood, or a reaction with metal. Harder to lift than a white bloom. | The edge as well as the face, to see if the darkness goes through. |
| Colour lost on the window side only | Light. Compare with cloth, a book, or a runner that covered part of the surface. | Both sides of the piece in the same session, so the difference is honest. |
| A scratch you can catch with a nail | Through the film and into the wood or the colour coat. | Close, and again with a ruler. Depth changes what a later finish can hide. |
| A cloudy, soft patch where a hot pan sat | Heat in the finish, sometimes with crushed fibres if the pan was also damp. | The shape of the object. A perfect circle is a clue. |
| A sticky, smeary shine | Polish, silicone, or a cleaner that never dried. Later finishes can crawl on silicone. | A note of what was sprayed in the last year. The residue itself may not show. |
Look along the surface, not only straight down
Hold a lamp to one side, low, and look across the face. Film finishes reveal orange peel, crazing, and shallow dents that an overhead room light hides. This is a looking test. It does not need a solvent. If you cannot see a scratch in raking light, it may be a colour loss in the stain rather than a groove.
White bloom on an older clear finish is often moisture in the film. Dark staining that follows the grain is more likely in the wood. The difference matters because rubbing a white bloom and sanding a black stain are not the same kind of work, and this page does not turn either of them into a recipe. If you are unsure which layer you are in, stop and keep the photographs. The finish note separates oil, wax, shellac, lacquer, and paint.
Sun fade is a map of the room
Light changes dyes and some woods unevenly. A runner, a tray, or a pile of papers leaves a darker or lighter ghost when it is lifted. That ghost is a record of where the light fell. It is not, by itself, dirt. Washing it harder will not put the colour back if the colour has been lost. On a veneered top, aggressive rubbing also risks cutting through a thin face. Read the veneer note before any abrasive pad.
What not to try first
- Flooding a mark with water to “see what happens”. You can turn a white ring into a dark one.
- Mixing household solvents on the face. A cotton bud in an unseen spot can still leave a dull circle, so even a small test is a mark.
- Melamine foam on a shine you want to keep. It is a fine abrasive and can flatten a film.
- Silicone spray “to feed the wood”. It can make a later finish bead and crawl. Note it if it has already been used.
- Dry-sanding older paint. The light and heat page explains why unknown paint on older pieces should not be turned into dust in a home.
A set of photographs that travels
Take five frames and stop: the whole piece; the marked area in ordinary light; the same area in raking light; an edge or underside; and any label, stamp, or pencil mark inside a drawer. Say in a caption what the room is like — south-facing glass, a radiator, a recent spill. That pack is more useful than a single filtered close-up.
If the mark is on leather or a coated fabric rather than a hard finish, use the leather note. Cloth seats are on the upholstery page. The catalogue of every note is here.