A paint scrape is a small window cut into a painted surface in which the paint layers have been removed one by one, so that the full sequence of layers becomes visible side by side — from the most recent to the oldest. It is the key tool of architectural paint research: from such a scrape you can read what colour a window, door or interior had in a given period. The Dutch term is kleurentrapje, literally “colour staircase”.
The result does look like a staircase: each little step of a few square centimetres shows one paint layer.
How it is made
Scalpel method. The layers are cut back one at a time with a scalpel. Each layer is numbered and assessed under a magnifying visor: colour, gloss level and condition — smooth or matt, brittle, crazed. A colour fan helps to record the colour as a code so it can be matched exactly later.
Abrasive method. A simpler, exploratory approach: rubbing back and forth exposes thin coloured lines, rather like a half-sucked gobstopper. Quick, but less accurate.
| Scalpel method | Layers cut back one at a time with a scalpel; each layer numbered and assessed under a magnifying visor for colour, gloss level and condition |
|---|---|
| Abrasive method | Simpler, exploratory approach: rubbing back and forth exposes thin coloured lines; quick, but less accurate |
The technical term for studying this build-up of layers is stratigraphy, a word borrowed from geology.
Where it is used
- Restoration of historic buildings — establishing which historic colour scheme to restore back to
- Interior research — recovering original colours of panelling, doors, beams and ceilings
- Building archaeology — the number and nature of the layers point to alterations and dates
Points to watch
- Choose sheltered, inconspicuous places — preferably internal work or a protected corner: outside, the upper layers are weathered and the colours misleading
- Make several scrapes — one scrape proves nothing; different components can have different histories
- Colour changes over time — yellowing of oil paint and accumulated dirt make old layers look darker than they were; a laboratory cross-section gives a more reliable picture
- Consent — on a listed building even investigative work is not automatically free of consent; agree it with the authority first
Related terms
- Architectural paint research
- Building archaeology
- Listed building
- Craquelure
- Panelling
- Pigment
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