A reference glossary covering the terminology you need to specify, buy, and troubleshoot organic pigments — from CI codes and CAS numbers to lightfastness ratings and REACH compliance. Click any term below to jump to its definition.

Azo Pigment Phthalocyanine Quinacridone Benzimidazolone Diarylide Monoazo Pigment DPP Pigment Naphthol Azo Lake Iron Oxide Lightfastness Blue Wool Scale Heat Stability Tinctorial Strength Dispersion Particle Size Distribution (PSD)Delta E (ΔE)CIE Lab Color Space Spectrophotometer Masstone Tint Strength Hegman Gauge Bleed Resistance Migration REACH RoHS 24 Banned Aromatic Amines SVHC GHS Certificate of Analysis (COA)Safety Data Sheet (SDS)FDA 21 CFR NSF Certification GPCB ETP CETP Masterbatch Letdown Ratio Flushing Surface Treatment Dispersant Binder Vehicle CI Code CAS Number MOQ PSD PY154 PY83 PR48:1 PR57:1 PR122 PR254 PB15:3 PG7 PG36

Pigment Chemistry

Azo Pigment: An organic pigment characterized by the azo group (-N=N-) connecting two aromatic rings, formed by diazotization of an aromatic amine and coupling with a phenol or naphthol. The largest pigment family by volume, including monoazo and diarylide (disazo) classes. Examples: PY1, PY3, PY12, PY74, PR48, PR57, PR112.
Phthalocyanine: A macrocyclic compound with a copper or other metal atom centered in a four-pyrrole ring system. Phthalocyanine pigments deliver the highest lightfastness (Blue Wool 8/8) and heat stability (300°C+) of any organic pigment family. Available only in blue (PB15 series) and green (PG7, PG36) shades.
Quinacridone: A premium organic pigment family derived from a quinacridone core with various substitutions. Produces clean reds, magentas, and violets with Blue Wool 7-8 lightfastness and 300°C+ heat stability. Examples: PR122, PR202, PR209, PV19. Standard for OEM automotive coatings.
Benzimidazolone: A high-performance pigment chemistry derived from benzimidazolone-based naphthols. Examples: PY151, PY154, PY175, PY180, PR175, PR176. Offers exceptional lightfastness (7-8 Blue Wool), heat stability (280-300°C), and chemical resistance — used in automotive coatings and engineering plastics.
Diarylide: A subclass of azo pigments with two diazonium-coupled aromatic rings, producing intense yellows and oranges. Examples: PY12, PY13, PY14, PY17, PY83 (HR — heat-resistant). Higher tinctorial strength than monoazo grades. PY83 is heat-stable to 280°C; standard diarylides decompose above 200°C.
Monoazo Pigment: Azo pigment with a single azo (-N=N-) group. Examples: PY1, PY3, PY74, PR2, PR3, PR4, PR112. Generally lower tinctorial strength than diarylide but cleaner shades. Used in printing inks, architectural paints, and textile printing.
DPP Pigment: Diketopyrrolopyrrole pigments — premium reds, oranges, and violets with excellent lightfastness (Blue Wool 7-8) and heat stability (300°C+). Examples: PR254, PR264, PO73, PO71. Used in OEM automotive coatings and engineering plastics.
Naphthol: Subclass of azo pigments coupled with naphthol-based naphtholates. Examples: PR2, PR3, PR4, PR8, PR12, PR112, PR170 (Naphthol AS). Bright reds with moderate lightfastness, commonly used in architectural paints, textile printing, and rubber compounding.
Azo Lake: An azo pigment metallized with calcium, barium, manganese, or strontium salts to form an insoluble lake pigment. Examples: PR48:1 (barium), PR48:2 (calcium), PR48:4 (manganese), PR53:1 (strontium), PR57:1 (calcium). Heavily used in printing inks.
Iron Oxide: Inorganic pigments based on iron oxides. PR101 (red), PY42 (yellow), PBr6 (brown), PBk11 (black). Excellent alkali stability and outdoor durability — workhorse for cement, concrete, and earth-tone applications. Not organic but commonly listed alongside organic pigments.

Performance & Technical Properties

Lightfastness: Resistance of a pigment to fading under UV exposure. Measured per ISO 105-B02 using the Blue Wool scale (1=poor, 8=excellent). Each step doubles UV resistance. Outdoor architectural paints need 6-7; OEM automotive needs 8/8.
Blue Wool Scale: ISO 105-B02 reference standard for lightfastness, comprising 8 dyed wool reference standards numbered 1 (worst) to 8 (best). Pigment fade rate is matched against these references in xenon-arc weatherometer testing. Industry-standard rating since 1965.
Heat Stability: Maximum temperature at which a pigment maintains color through processing in a polymer or coating without decomposition or shade shift. Measured by injection moulding the pigment into target polymer at progressive temperatures. PVC: 200-220°C minimum; HDPE/PP: 240-280°C; engineering plastics: 280-300°C.
Tinctorial Strength: The color-imparting power of a pigment per unit weight, typically measured against a calibrated reference at standard pigment loading. Higher tinctorial strength means less pigment is needed to achieve a target color depth — directly affects formulation cost.
Dispersion: The process of breaking down pigment agglomerates into individual primary particles and stabilizing them in a binder or polymer. Three steps: wetting, grinding, stabilization. Poor dispersion causes settling, filter clogging, weak color strength, and gloss reduction.
Particle Size Distribution (PSD): The statistical distribution of pigment particle sizes in a batch, measured by laser diffraction. Common metrics: d50 (median), d90 (90th percentile), specific surface area (BET). Coatings: d50 0.1-0.3 micron typical. Powder coatings: d50 less than 1 micron required.
Delta E (ΔE): Numerical color difference in CIE Lab color space, calculated as Euclidean distance between two L*a*b* coordinate points. ΔE less than 1 = imperceptible; less than 2 = acceptable for premium; 2-5 = noticeable; 5+ = clearly different. Standard QC tolerance for premium pigments: ΔE less than 1.0.
CIE Lab Color Space: International color measurement coordinate system: L* (lightness 0-100), a* (green-red -128 to +128), b* (blue-yellow -128 to +128). Standardized in 1976 by Commission Internationale de l'Éclairage. Most spectrophotometers report color in CIE Lab.
Spectrophotometer: Instrument that measures spectral reflectance of a sample under controlled illumination, computing CIE Lab color values. Used for batch QC, color matching, and ΔE measurement against reference standards. Common configurations: D65 illuminant, 10° observer.
Masstone: Color of a pigment in concentrated form (typically 100% pigment loading or saturated tint). Contrasted with tint tone (diluted). Both are reported on a Certificate of Analysis. Color shift between masstone and tint tone reveals undertone characteristics important for color formulation.
Tint Strength: Color strength of a pigment when blended with white (typically TiO2) at standardized ratios. A measure of how strongly the pigment colors a white base. Reported with masstone as part of QC color characterization.
Hegman Gauge: A grindometer used to measure the fineness of pigment dispersion in liquid coatings. The pigment-binder mixture is drawn down a tapered wedge; the point at which agglomerates appear gives the grind reading (1=coarse to 8=very fine). Coatings target 6-7 minimum.
Bleed Resistance: Resistance of a pigment to migrating from its host coating or polymer into adjacent layers or media. Critical for laminates, multi-layer packaging, plasticized PVC, and rubber. Bleed-resistant grades are typically benzimidazolone, quinacridone, or phthalocyanine families.

Regulatory & Compliance

Migration: Unwanted movement of pigment or pigment additive from a coating, polymer, or rubber into adjacent layers, surfaces, or food contact material. Measured by accelerated migration tests under heat or solvent contact. Key concern in food-contact and laminated packaging applications.
REACH: EU Regulation EC 1907/2006: Registration, Evaluation, Authorisation and Restriction of Chemicals. Requires chemical manufacturers and importers to register substances above 1 tonne/year. For pigment buyers, REACH requires no SVHC content above 0.1% threshold and freedom from the 24 banned aromatic amines.
RoHS: EU Directive 2011/65/EU: Restriction of Hazardous Substances. Restricts 10 substances in electrical and electronic equipment including lead, mercury, cadmium, hexavalent chromium, and certain phthalates. Modern organic pigments are inherently RoHS compliant.
24 Banned Aromatic Amines: List of 24 specific aromatic amines (benzidine, 2-naphthylamine, MDA, etc.) banned from being released by azo dyes and pigments under EU Directive 2002/61/EC. Tested per EN ISO 17234 (leather) and EN ISO 14362 (textiles) at 30 mg/kg threshold. All Kanani pigments are certified free.
SVHC: Substance of Very High Concern under REACH — substances that are CMR (carcinogenic, mutagenic, toxic for reproduction), PBT (persistent, bioaccumulative, toxic), or vPvB (very persistent, very bioaccumulative). REACH Candidate List restricts use; SVHC presence above 0.1% must be declared.
GHS: Globally Harmonized System of Classification and Labelling of Chemicals — UN standard for chemical safety classification, hazard pictograms, and Safety Data Sheet (SDS) format. SDS sections 1-16 are standardized globally. All Kanani pigments ship with GHS-compliant SDS.
Certificate of Analysis (COA): Batch-specific document confirming a pigment batch meets specified test parameters (color, particle size, purity, moisture, etc.). Required for traceability in regulated industries. Kanani provides a unique COA per batch with every shipment.
Safety Data Sheet (SDS): 16-section document per GHS standard documenting chemical hazards, handling, transport, regulatory information, and ecotoxicology. Required by law for any chemical product. Updated whenever formulation, classification, or regulatory status changes.
FDA 21 CFR: US Food and Drug Administration regulation 21 Code of Federal Regulations covering food contact materials. Specific pigments approved for food contact are listed in 21 CFR Part 178. Compliant pigments include PY138, PY110, PR254, certain phthalocyanines.
NSF Certification: Independent third-party certification by NSF International. NSF/ANSI 61 covers materials in contact with potable drinking water — required for HDPE pipe pigments in many markets. Complementary to but distinct from REACH and FDA.
GPCB: Gujarat Pollution Control Board — the Indian state regulatory body governing chemical manufacturers in Gujarat. Compliance covers air emissions, effluent treatment, hazardous waste disposal, and environmental clearance. Kanani Dyes Chem LLP is fully GPCB compliant with in-house ETP.
ETP: Effluent Treatment Plant — facility for treating chemical manufacturing wastewater before discharge. Combined biological, chemical, and physical treatment to meet statutory discharge standards. Kanani operates an in-house ETP plus is a CETP cooperative member.

Application Terms

CETP: Common Effluent Treatment Plant — shared treatment facility for chemical industrial estates. Members route their pre-treated effluent to CETP for final treatment. Kanani is a CETP cooperative member in addition to operating in-house ETP.
Masterbatch: Concentrated pigment dispersed in a polymer carrier (typically 20-50% pigment loading), used as a colorant additive in plastic processing. Buyers add masterbatch at 1-5% to base polymer to achieve target color. Heat stability of pigment must match end-product processing temperature.
Letdown Ratio: The dilution factor at which masterbatch is added to base polymer. Common ratios: 1:50 (2% loading), 1:100 (1% loading). Higher pigment concentration in the masterbatch enables higher letdown ratios — preferred for production efficiency.
Flushing: Manufacturing process for converting wet pigment slurry directly into oil-vehicle pigment paste, eliminating drying. Flushed pigments are pre-dispersed in oil or water vehicle, simplifying ink and paint manufacture. Common for offset printing inks and water-based coatings.
Surface Treatment: Functional coating applied to pigment particles during manufacture to improve dispersion in specific binder systems. Common treatments: resin coating (solvent-borne), surfactant coating (waterborne), silane (specialty), fatty acid (general). Same pigment can be supplied in multiple surface-treated variants.
Dispersant: Polymeric or surfactant additive that stabilizes pigment dispersions through steric or electrostatic separation of particles. Common: polyacrylates, polyurethanes, polyesters. Dose 0.2-2% on pigment weight. Critical for waterborne coatings and high-pigment-loading systems.

Industry Abbreviations

Binder: Polymer or resin that holds pigment particles in a coating film and adheres them to a substrate. Examples: acrylic (waterborne paint), alkyd (solvent-borne paint), epoxy (powder coating, adhesive), polyester (powder coating), nitrocellulose (printing ink), PVC (plastisol).
Vehicle: Liquid medium in a coating, ink, or paint that carries the pigment during application and evaporates or cures to leave the dry film. In paint terminology: solvent-borne (organic solvent), waterborne (water + co-solvent), 100% solids (no volatile carrier).
CI Code: Color Index code — international classification system for pigments and dyes, maintained by Society of Dyers and Colourists. Format: CI Pigment [Color] [Number], e.g. CI Pigment Yellow 154 = PY154. Universal pigment identifier across all manufacturers.
CAS Number: Chemical Abstracts Service Registry Number — unique identifier for a specific chemical compound. Format: XXXX-XX-X. Example: PY154 = CAS 68134-22-5. Used for regulatory submissions, SDS preparation, and customs documentation.

Specific Pigment Grades

MOQ: Minimum Order Quantity — the smallest batch a supplier will produce or ship, typically expressed in kilograms. Standard pigment grades: 25 kg minimum. Specialty grades may require 100 kg+. MOQ exists because pigment manufacture has fixed batch costs (cleaning, QC, documentation).
PSD: Particle Size Distribution — see entry above. PSD is critical for dispersion behavior, color development, and powder coating compatibility.
PY154: Pigment Yellow 154 — benzimidazolone yellow, CAS 68134-22-5, the premium yellow for automotive coatings, engineering plastics, and high-performance industrial paints. Blue Wool 7-8 lightfastness, 300°C heat stability.
PY83: Pigment Yellow 83 — diarylide HR (heat-resistant) yellow, CAS 5567-15-7, the workhorse heat-stable yellow for plastic masterbatch and architectural paints. Blue Wool 6-7 lightfastness, 240-280°C heat stability.
PR48:1: Pigment Red 48:1 — barium salt of BONA azo, CAS 7585-41-3, bright bluish red for offset/flexo printing inks, packaging, and architectural paints. Blue Wool 5-6 lightfastness.
PR57:1: Pigment Red 57:1 — calcium salt of BONA azo, CAS 5281-04-9, the industry-standard process magenta for CMYK offset printing. Cleaner rubine shade than PR48:1 with marginally better lightfastness.
PR122: Pigment Red 122 — quinacridone magenta, CAS 980-26-7, the premium magenta for OEM automotive coatings, engineering plastics, and high-end architectural paints. Blue Wool 7-8 lightfastness, 300°C+ heat stability.
PR254: Pigment Red 254 — DPP red, CAS 84632-65-5, premium scarlet red for automotive coatings, engineering plastics, and specialty industrial paints. Blue Wool 8 lightfastness, 300°C+ heat stability.
PB15:3: Pigment Blue 15:3 — beta crystal copper phthalocyanine, CAS 147-14-8, the most-used blue pigment globally. Process cyan in CMYK printing, plus paints, plastics, inks across all applications. Blue Wool 8/8, 300°C+ heat stability.
PG7: Pigment Green 7 — chlorinated copper phthalocyanine, CAS 1328-53-6, the workhorse green pigment for paints, plastics, inks, textiles, construction. Blue Wool 8/8, 300°C+ heat stability. Cost-effective alternative to PG36.
PG36: Pigment Green 36 — brominated/chlorinated copper phthalocyanine, CAS 14302-13-7, premium yellower-shade green for automotive and high-end applications. Blue Wool 8/8, 300°C+ heat stability. ~2x cost of PG7.

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