EDITORIAL INDEX
The rare colour index
Colour becomes rare for specific reasons: a scarce raw material, a difficult synthesis, a proprietary process, a regulatory restriction, or a production volume too small for ordinary distribution. This index groups genuinely scarce colour by family and states, in each case, whether the material can be obtained commercially.
Rare blues
FOUR MECHANISMS, FOUR PRICES
YInMn Blue
Indium content and small production volumes set the price. Stable, NIR-reflective, industrially relevant.
SOURCING ENQUIRY
Natural ultramarine
Historically the most expensive pigment in Europe. Scarcity is in the purification, not just the stone.
SOURCING ENQUIRY
Azurite
A mineral blue that behaves differently in every binder. Conservation work still specifies it deliberately.
SOURCING ENQUIRY
Structural blue
Colour from interference rather than pigment. Proprietary as an OEM finish; the physics is general.
TECHNICAL REFERENCE
Extreme blacks & rare reds
REFLECTANCE AT ONE END, TOXICITY AT THE OTHER
Ultra-black coatings
The lowest-reflectance technologies are grown on a part, not sprayed. Very effective sprayable blacks do exist.
SOURCING ENQUIRY
Candy red systems
Depth comes from transparent layers over a reflective base — and from spraying every pass identically.
SOURCING ENQUIRY
Historical reds
Several are mercury or lead compounds. Discussed for identification; modern equivalents supplied instead.
PROFESSIONAL ENQUIRY
Gold & bronze effects
Metal-flake and coated-mica golds. Appearance depends far more on orientation than on the pigment alone.
SOURCING ENQUIRY
Colour that moves
ANGLE, TEMPERATURE AND LIGHT AS VARIABLES
Interference & iridescent
Thin-film platelets whose reinforced wavelength changes with viewing angle.
SOURCING ENQUIRY
Colour-shift systems
Multi-layer platelets producing a deliberate travel between two named hues.
SOURCING ENQUIRY
Thermochromic
Temperature-activated change. Switch point and cycle life must be specified, not assumed.
SOURCING ENQUIRY
Phosphorescent
Afterglow pigments where particle size trades brightness against surface finish.
SOURCING ENQUIRY
Working with a colour that is hard to obtain?
Send the reference, the substrate and the quantity. We will say what is obtainable and what should be substituted.