Basecoat
Definition
The colour-bearing layer in automotive OEM paint; thin (10-30 µm), thermoplastic acrylic binder, contains colour and effect pigments.
- Layer role
- Colour-bearing layer in OEM automotive paint
- Thickness
- Approximately 10 to 30 micrometres
- Binder type
- Thermoplastic acrylic
- Contains
- Colour and effect pigments
Common questions
Why is the basecoat significant for a hit-and-run paint comparison?+
Its pigment combination and effect particles, such as metallic flake or pearlescent additives, are highly specific to a manufacturer's colour code and production period, so matching the basecoat pigment package is often the strongest single point of comparison in the paint layer sequence.
How is the basecoat distinguished from the clearcoat sitting above it under a microscope?+
The clearcoat is transparent and carries no colour pigment, so under cross-section microscopy the basecoat is the first pigmented layer beneath it, identified by its colour and the presence of pigment particles rather than by thickness alone since thickness varies between models.
Related terms
- Alkyd Resin
- A polyester binder modified with fatty-acid chains from drying oils; cures by oxidative crosslinking and is characterised by FTIR ester carbonyl absorption...
- Binder
- The polymer matrix that holds pigments in place and bonds the paint to the substrate. Identifies paint type (alkyd, acrylic, polyurethane, epoxy)...
- Clearcoat
- The transparent outermost layer of automotive OEM paint; thermoset acrylic-melamine, 40-60 µm, provides UV resistance and gloss.
- Effect Pigment
- Aluminium flake or TiO2-coated mica used in metallic and pearlescent automotive finishes; identified by SEM morphology and EDS elemental composition.
- Electrocoat (E-Coat)
- The first layer in automotive OEM paint, applied by cathodic electrodeposition of an epoxy-amine coating onto the bare steel shell; 15-25 micrometres...
- ENFSI EPG
- Expert Working Group on Paint (European Network of Forensic Science Institutes); produced the European paint-examination protocol and promoted EUCAP development.
- PDQ
- Paint Data Query database (RCMP-maintained). Cross-referenced from glass work when a vehicle is identified through paired glass and paint evidence.
- Phthalocyanine
- Highly stable organic pigment providing intense blue (PB15, copper phthalocyanine) and green (PG7) colours; identified by Raman bands at 680 and 748...
- Refinish Paint
- Paint applied in body-shop repair; typically 2K polyurethane, chemically distinct from OEM acrylic-melamine; adds extra layers visible in cross-section.
- SWGMAT
- Scientific Working Group for Materials Analysis, a US forensic science standards body (now succeeded by the OSAC Explosives Subcommittee). Published the Forensic...
- TiO2 Polymorph
- Titanium dioxide exists as rutile (Raman 143, 447, 612 cm-1) or anatase (Raman 144, 197, 399, 513 cm-1); the polymorph distinguishes premium...