Paint
Definition
Pigmented liquid coating that dries to an opaque, coloured solid film. Built from four functional components: binder, pigment, solvent (vehicle), and additives.
- Core components
- Binder, pigment, solvent, additives
- Binder role
- Forms the dried film and holds pigment
- Forensic use
- Layer sequence comparison in transfer evidence
- State at use
- Applied liquid, dries to solid film
Common questions
Which component of paint carries the most forensic discriminating power?+
Binder chemistry, identified by FTIR, is usually the most discriminating because manufacturers vary resin formulations by product line and model year, while pigments and additives are shared more widely across brands.
Why does the additive component matter to an examiner if it's a minor fraction of the paint?+
Additives such as driers, UV stabilisers, and anti-settling agents are proprietary to a manufacturer's formulation and can distinguish two paints that otherwise share the same binder and pigment, refining a match beyond colour alone.
Related terms
- Binder
- The polymer matrix that holds pigments in place and bonds the paint to the substrate. Identifies paint type (alkyd, acrylic, polyurethane, epoxy)...
- Cross-Section Mount
- Embedding a paint chip in resin, polishing to a flat face, and viewing under reflected light at 100 to 400 times magnification...
- Lacquer
- Clear or pigmented coating that dries purely by solvent evaporation (no chemical cure). Nitrocellulose and acrylic lacquers are the classic examples. Fast...
- PDQ (Paint Data Query)
- RCMP-maintained international automotive paint database. Stores binder, pigment and layer data for vehicle original-equipment finishes from major manufacturers. Used to narrow a...
- Pigment
- Insoluble particles that give colour and opacity. Titanium dioxide (white), iron oxides (red/brown), carbon black (black), organic colorants (blues, reds). SEM-EDX reports...
- Pyrolysis GC-MS
- Heating a tiny polymer sample (about 1 microgram) to roughly 600 to 800 degrees Celsius in an inert atmosphere, separating the volatile...
- Varnish
- Transparent, hard protective film made from a drying oil, resin and solvent. Cures by oxidation (oil varnish) or polymerisation (polyurethane varnish). Used...