00 · IN THREE MINUTES
The answer in three steps
- 1A pigment is a coloured material; a attaches it to a surface.
- 2Inorganic minerals are often durable, but some react with light, moisture, acids or neighbouring compounds.
- 3What survives is a filtered sample, so a colourless statue may once have been painted.
01 · COLOUR IS A MATERIAL SYSTEM
Colour is a material system
Ochres, carbon blacks, copper minerals and manufactured compounds have different crystal structures and particle sizes. Egg, oil, gum, wax or plaster changes how those particles are held and exposed.
02 · STABILITY IS CHEMICAL
Stability is chemical
Iron-oxide ochres and carbon can be very persistent under suitable conditions. Vermilion may darken, lead pigments transform, and copper greens can react with moisture or chlorides.
Colour is a material system
Ochres, carbon blacks, copper minerals and manufactured compounds have different crystal structures and particle sizes. Egg, oil, gum, wax or plaster changes how those particles are held and exposed.
pigment plus binderStability is chemical
Iron-oxide ochres and carbon can be very persistent under suitable conditions. Vermilion may darken, lead pigments transform, and copper greens can react with moisture or chlorides.
chemical stabilityLight supplies activation energy
Ultraviolet and visible light can break molecular bonds or drive reactions. Many organic dyes fade faster than mineral pigments, especially when the binder also oxidizes.
light exposureBurial can protect and destroy
Dark, stable burial may shield colour from light, yet groundwater, salts, microbes and changing oxygen conditions can dissolve, migrate or replace compounds.
material analysis03 · LIGHT SUPPLIES ACTIVATION ENERGY
Light supplies activation energy
Ultraviolet and visible light can break molecular bonds or drive reactions. Many organic dyes fade faster than mineral pigments, especially when the binder also oxidizes.
04 · BURIAL CAN PROTECT AND DESTROY
Burial can protect and destroy
Dark, stable burial may shield colour from light, yet groundwater, salts, microbes and changing oxygen conditions can dissolve, migrate or replace compounds.
05 · ANALYSIS RECOVERS INVISIBLE TRACES
Analysis recovers invisible traces
Microscopy, X-ray methods, Raman spectroscopy and elemental mapping identify grains and alteration products. Evidence can establish former colour without guaranteeing exact original saturation.
06 · SOURCES AND EVIDENCE
Sources and evidence
The explanation follows the evidence chain below. Links open the original source.
- 01Artists' PigmentsINSTITUTIONAL EXPLAINER ↗
Supports a specific claim or evidence boundary used in this article.
- 02The Materials of the ArtistSCHOLARLY MONOGRAPH ↗
Supports a specific claim or evidence boundary used in this article.
- 03Raman microscopy of pigmentsPEER-REVIEWED REVIEW ↗
Supports a specific claim or evidence boundary used in this article.