Short answer
A paint film is pigment held in a binder, and the colour it shows depends on more than the pigment: on the sheen, which is set by how much binder covers the pigment grains; on the surface underneath and how the film was applied; on the light; and on the batch, since every colour is made to a tolerance. With age it is usually the binder and the top of the film that move first — chalking, dulling, burnishing and yellowing — and only then the pigment. Which of these happens depends on the binder type, the exposure and how the surface is used.
Relative to other materials in this section, not a measurement of a particular product.
| Process | What you see | Driven by | Slowing it |
|---|---|---|---|
| Chalking | Loose pale powder; colours look paler and hazier | Ultraviolet breaking down the binder at the surface and freeing pigment | Exterior-grade binders; remove the chalk before repainting |
| Gloss loss in weathering | A dulled surface that looks lighter and less saturated | Sunlight, oxygen, heat and moisture roughening the top of the film | Durable exterior systems; cleaning shows how much is dirt and chalk |
| Burnishing | Shiny patches where a low-sheen paint is rubbed or scrubbed | Rubbing, abrasive cleaning and furniture contact | A higher-sheen finish in busy areas; soft cloths and mild cleaners |
| Binder yellowing (oil and alkyd) | Whites and clear varnishes turn cream or yellow | The curing chemistry of oil and alkyd binders, strongest away from light and with heat | Water-borne paint where whiteness matters, especially in unlit areas |
| Pigment fading | Paler or shifted colour on the exposed side | Light acting on pigments of limited lightfastness | Lightfast pigments for sunny and exterior work |
Paint makers describe a formulation by its pigment volume concentration: the share of the dry film's volume that is pigment rather than binder. Where binder is plentiful it floods over the pigment and dries to a smooth skin, which reflects like a mirror and reads as gloss. Where binder is scarce, pigment grains stand proud of the surface and scatter light, which reads as matt. That one ratio is why sheen and durability travel together — a film rich in binder is tougher and easier to wipe — and why the trade names for sheen are unreliable guides: matt, eggshell, satin, silk and semi-gloss are not standardised, and one maker's satin is not another's.
A shade card is a different object from a painted wall: printed or sprayed on card, at one sheen, seen under shop lighting. A paint manufacturer's own guidance lists what moves the applied colour away from it — the substrate, the gloss level, the lighting, the thickness of the film, the angle of view, and even the tool, since a brushed coat can look a different colour from a rolled one. On top of that sits tolerance. Every batch is made to within a permitted distance of the standard, so two batches differ slightly, and factory-made paint differs from the same colour tinted in store. The practical rules follow directly: finish a visible area from one batch, change batches at a corner, and touch up from the original tin.
Paint does not hide the shape of what it covers; with sheen, it advertises it. Plasterboard manufacturers describe 'critical lighting' — daylight from tall windows or lamps mounted close to a wall, striking the surface at a low angle — as the condition in which joints, fixings and filled patches show through the decoration as bands of shadow. Their guidance is that flat paint over a standard finish is acceptable in ordinary light, but that sheen, dark deep-tone colours or side lighting call for a skim coat over the whole surface first, and that even this reduces the effect rather than guaranteeing a flawless wall. The table of light and finish cases on this page sets out which combination produces which problem.
Most of what goes wrong with a painted colour is a change in the film rather than in the colourant. Outdoors, ultraviolet breaks down binder at the surface: gloss falls and loose pigment appears as chalk, and both lay a pale veil over a colour that may still be intact underneath. Indoors, flat paint burnishes into shiny, darker-looking patches where it is rubbed or scrubbed. Oil and alkyd paints and varnishes yellow because of the way they cure, and they do it most where light is kept off them — behind pictures, inside cupboards — and near heat. Genuine pigment fading comes on top of these, in colours made with less lightfast pigments. Telling them apart matters because the remedies differ; the failure table on this page gives the test for each.
| Surface and finish | Light | Viewed | What changes | What to do | Evidence |
|---|---|---|---|---|---|
| Dark gloss paint, lacquer, laminate or moulded plastic (gloss) | Single small source (spotlight, downlight, bare lamp) | At the mirror angle of the light | A bright image of the lamp replaces the colour at that spot; the darker the colour, the stronger the contrast between the hot spot and the surface around it. | Move or diffuse the lamps so their mirror angle misses the usual viewpoint, or choose a satin or matt finish for dark colours under spotlights. | Strong |
| Dark gloss paint, lacquer, laminate or moulded plastic (gloss) | Single small source (spotlight, downlight, bare lamp) | Face-on, away from any reflection | Away from the reflection the colour looks darker and more saturated than the same colour in a matt finish. | Compare samples in the finish that will be used, held at the same angle and away from reflections. | Strong |
| Matt paint or any matt coating (matt) | Any light | Any angle | Looks lighter and less saturated than the same colour in gloss, and changes little as the viewpoint moves. | Accept the lift as the price of an even, reflection-free wall, or step up to eggshell or satin where a dark colour needs depth. | Strong |
| Gloss or semi-gloss paint, lacquer or laminate (gloss) | Diffuse or large-area light (overcast sky, big window, lit ceiling) | From an angle | A large pale reflection of the window, sky or lit ceiling lies over part of the surface, and the colour there looks lighter and washed out. | Keep gloss for surfaces that do not face large windows at the mirror angle, or lower the sheen; blinds change the reflection, not the paint. | Moderate |
| Matt, eggshell or satin paint and other low-sheen coatings (satin or eggshell) | Any light | Along the surface (grazing) | Seen along its length, a low-sheen surface shows a sheen it does not show face-on, and looks paler there. | Judge sheen by sighting along the sample as well as facing it, and choose a flatter finish for long walls seen end-on. | Moderate |
| Two painted surfaces, or paint beside another material, matched by eye | Two or more different sources | Any angle | A pair that matches under one light can separate under another, and the direction of the mismatch depends on the two formulations. | Check matches under every light the surfaces will be seen in, and touch up from the original tin rather than a re-mixed one. | Strong |
| White and near-white matt paint (matt) | Two or more different sources | Any angle | Takes on the colour of whichever light dominates each part of the room: warmer near a warm lamp, cooler near a window. | Judge whites in the room's own light at the times it is used; bring the lamps closer to one colour temperature if the split is unwelcome. | Moderate |
| Painted plaster or plasterboard meant to be flat (satin or eggshell) | Raking light (along the surface) | Any angle | Joints, fixings, ridges and filled patches appear as bands of shadow and highlight that are invisible in frontal light; sheen and dark colours make them stronger. | Ask for a full skim coat on walls that take side light or will carry sheen or dark colours; use flat paint there; move wall-washers away from the wall. | Strong |
| What goes wrong | How to recognise it | Can it be reversed? | What to do |
|---|---|---|---|
| Fading | Compare with an area the light never reached — under a mount, a hem, a cushion or the back of the object. The change follows exposure, has soft edges and affects only the lit face. | Irreversible. The colourant is destroyed, not hidden. Colour returns only by re-dyeing, repainting or retouching — that is, by adding new colourant. | Accept, or renew the colour: repaint, re-dye or reupholster; For valued objects, keep the original in low light and display a copy |
| Yellowing | The shift is towards yellow or brown and is strongest in whites and clear layers. Note where it is worst: on the sunlit face, or — for oil and alkyd paint — in the places light never reaches. | Partly reversible. Whether the yellow is in a layer that can be removed or renewed — a varnish, a coat of paint — or in the object's own substance, as with paper, plastic and silk, where it stays. | Repaint or recoat a yellowed finish; Leave removal of a yellowed varnish on a painting to a conservator; Replace yellowed plastic parts; surface treatments do not restore the material |
| Uneven ageing and shadowing | The outline matches something that was there. This is the clearest evidence of how far the rest of the surface has moved, because the patch records the earlier colour. | Partly reversible. The exposed area cannot be returned to its earlier colour. Because the change is cumulative, uncovering the protected patch lets it change too, which may narrow the difference without removing it. | Expose the protected area and wait, for materials that are still changing; Refinish the whole surface: sand and refinish wood, repaint a wall |
| Gloss loss and burnishing | View the surface along its length against the light: the change is in how it reflects, not in its colour face-on. Dark colours show it most. | Partly reversible. Only the surface is affected, so a new coat restores it; but a burnished patch cannot be made matt again, and touching up a patch rarely matches the sheen around it. | Repaint the whole wall section or panel, not the patch; Clean an exterior coating first: part of the dullness may be dirt and chalk |
| Chalking | Rub a fingertip or a dark cloth across the surface: chalk transfers. This is how the standard test methods assess it. | Partly reversible. The loose powder can be cleaned off, which recovers some colour, but the binder that has eroded is gone and the surface will chalk again. | Wash off the chalk to see what colour remains; Clean the chalk off before recoating |
| Colour drift between batches and over time | The difference follows a joint, a panel, a course or a wall — the boundary between two supplies — and is there from the first day or from the day of the repair. | Partly reversible. Nothing brings two batches together; the mismatch is removed only by re-coating or replacing up to a natural break such as a corner. | Repaint or replace to the nearest corner or joint, not a patch; For tile and other units sold with a stated variation class, look at several pieces together before laying, not one |
| Ultraviolet damage to the material | A change of texture or strength as well as of colour, confined to the exposed face, on materials known to absorb ultraviolet. | Irreversible. Broken polymer and fibre cannot be mended. A damaged surface layer can sometimes be removed or recoated, which is replacement, not repair. | Recoat or refinish once the degraded layer has been removed; Replace embrittled parts |
| Heat damage | The change is centred on a heat source and fades with distance from it, and it occurs with or without light. | Irreversible. Distorted plastic, migrated dye and a thermally yellowed material do not go back. Paint can be renewed, and will yellow again if the heat remains. | Repaint, accepting that the cause is still there; Replace distorted plastic and dye-stained fabric |
| Cleaning, abrasion and impact damage | The pattern follows contact: where a glass stood, where a cloth was rubbed, along seams and edges, across the whole face that was blasted. The change can usually be felt as well as seen. | Partly reversible. Whether there is material left to refinish. Etched marble can be re-honed and repolished by a specialist; the fired face of a brick or a worn plated layer cannot be put back. | Professional refinishing for etched or scratched stone; Repaint a burnished wall section; Accept abrasive damage to masonry; further cleaning makes it worse |
Why: The new paint differs in film thickness, sheen or batch from the aged coat around it.
Fix: Repaint the whole wall to its corners from one tin.
Why: Light from a window or wall-washer runs along the surface; sheen makes it worse.
Fix: Skim the whole surface before painting, and use a flat finish on side-lit walls.
Why: An oil or alkyd binder yellows where light is kept off it.
Fix: Repaint with a water-borne paint in unlit places.
Each statement is labelled by kind — established fact, a standard’s requirement, observed market data, a convention, or Colourwise’s own interpretation or analysis — with the strength of the evidence behind it.
FactModerate evidence
A paint's sheen is determined mainly by the ratio of binder to pigment: more binder gives a smoother, glossier surface, while less binder leaves pigment grains exposed, scattering light and giving a matt finish; the common sheen names are not standardised between manufacturers.
Source: Paint sheen
FactModerate evidence
A paint manufacturer advises that applied colour can differ from a shade card because of substrate, gloss level and lighting, that every colour is produced to a tolerance so batches and factory-made versus in-store-tinted paint may differ, and that a change of batch should be made at a corner.
Caveat: One manufacturer's guidance; tolerances themselves are not published.
ConventionModerate evidence
Plasterboard manufacturers advise a skim coat over the whole surface (a Level 5 finish) where walls will carry gloss or dark, deep-tone paint or will be lit at a low angle, because joints and fixings otherwise show through the decoration.
Caveat: North American practice based on the Gypsum Association's GA-214, which Colourwise has read only in manufacturers' summaries.
Source: Gypsum Board Finish Levels (guide to GA-214); Wallboard Finished Appearance: Managing Expectations and Best Practices (white paper)
FactModerate evidence
Alkyd and oil-based paints tend to yellow because of their curing mechanism, particularly in areas not exposed to light such as behind pictures and inside cupboards, and with heat from stoves, radiators and ducts.
Source: Yellowing (paint problem solver)
FactModerate evidence
Burnishing is an unwanted increase in the gloss of a paint film where it has been rubbed, scrubbed or brushed against, associated with flat paint in busy areas and with abrasive cleaning.
StandardStrong evidence
ASTM D4214 assesses chalking of white or tinted exterior paint by transferring the chalk to a fabric, a fingertip or adhesive tape and comparing it with photographic references or a reflectance table.
Caveat: From the standard's public scope statement; the method itself was not read.
Source: ASTM D4214-23 Standard Test Methods for Evaluating the Degree of Chalking of Exterior Paint Films
Reviewed 1 October 2026. Colourwise summarises its sources in its own words and does not reproduce standards text or proprietary colour data. Spotted an error? Tell us.