pigment
Let an agent explain pigments and how they differ from dyes, relay chemistry, kinds, properties and history from materials and art sources, describe biological pigments, and distinguish pigments from dyes, colourants in general and structural colour.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent explain pigments and how they differ from dyes, relay chemistry, kinds, properties and history from materials and art sources, describe biological pigments, and distinguish pigments from dyes, colourants in general and structural colour.
A material that imparts colour by selectively absorbing and reflecting light and that is insoluble in the medium in which it is dispersed, unlike a dye which dissolves, including inorganic pigments such as ochres, titanium dioxide and ultramarine, organic pigments such as phthalocyanines, and biological pigments such as chlorophyll, melanin and carotenoids; pigments are used in paints, inks, plastics, cosmetics and art, and their history spans from prehistoric ochre to synthetic colours.
What it is for: Colouring materials.
It can be explain the class; relay chemistry and kinds; describe biological pigments; distinguish related concepts.
Distinguishing features
Insoluble
Light absorption
Inorganic, organic and biological
Ancient and modern
What it looks like
Coloured powders dispersed in paints and other media.
Physical character
titanium dioxide production: millions of tonnes per year note - largest white pigment
oldest ochre use: over 100000 years ago note
Colour Index: standard pigment classification note
How it is recognised
Insoluble colouring material
Ochres, titanium dioxide, ultramarine, phthalocyanines, chlorophyll, melanin
Dyes dissolve; colourant is the general term; structural colour comes from microstructure
Related models
is a kind of - in registry terms
is contrasted with - which dissolves
is used in - and inks and plastics
is exemplified by - the main white pigment
In practice
Families and kinds
inorganic pigments such as ochres, oxides and ultramarine
organic synthetic pigments such as azo and phthalocyanine pigments
biological pigments such as chlorophyll, melanin, carotenoids and haemoglobin
historical pigments such as lapis lazuli and lead white
effect pigments such as metallic and pearlescent
Standards and regulation
Colour Index International
Regulations on toxic pigments such as lead and cadmium
Cosmetics and food colour approvals
Failure modes and hazards
Toxicity of some heavy metal pigments
Confusing pigments with dyes
Fading and lightfastness problems
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.pigment-substance
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Understand What a pigment is.
Science.
Definition
Definition.
Definition
Definition.
- What is a pigment, and how does it differ from a dye, a colourant in general and structural colour? definition
- Is the question about chemistry, art, biology or a specific pigment? boundary
Kinds
Kinds.
Kinds
Kinds.
- What are inorganic, organic, biological, historical and effect pigments? definition
- Which entry fits the specific pigment? action
Science Chemistry and properties.
Science.
Colour
How pigments colour.
Colour
Colour.
- How do pigments absorb and scatter light, and what determines hue, opacity and lightfastness? provenance
- Which references are standard? provenance
Biology
Biological pigments.
Biology
Biology.
- What roles do chlorophyll, melanin, carotenoids and other biological pigments play? provenance
- Which sources are cited? provenance
Use Uses.
Application.
Industry
Industry.
Industry
Industry.
- How are pigments used in paints, inks, plastics and cosmetics, and how are they regulated? provenance
- Which entry fits paint? action
Art
Art and conservation.
Art
Art.
- How have artists used pigments, and how do conservators identify them? provenance
- Which entry fits art conservation? action
Context History and safety.
Context.
History
History.
History
History.
- How did pigments develop from ochre and lapis lazuli to synthetic colours such as Prussian blue and phthalocyanine? provenance
- Which entry fits the history of pigments? action
Safety
Safety.
Safety
Safety.
- Which pigments are toxic, and how are they regulated? provenance
- Which entry fits lead paint? action
What the second pass must settle
- Should inorganic pigment, organic pigment and biological pigment be separate primary entries?
- How should materials and art sources be linked?
- How should the Colour Index be linked?