Overview
Paint coatings can be divided into the following broad generic groups:

Primers are primarily deposited to achieve adhesion to difficult substrates. They can also be used as high build films for "filling" minor defects on the moulding.

Substrate Material	Comments
ABS, PC, ABS/PC blends,	Most base-coats will adhere directly to these polymers
Noryl, Nylon, Glass filled compoites, Carbon fibre composites, Polyesters, Polyurethanes, Acrylics, HIPS, PVC	Some base coats are formulated to adhere directly to these substrates, others may require a primer to be applied .
Polypropelyne, Acetal,	Difficult to achieve adhesion, will require special primers.

Most paints adhere well to a wide range of engineering polymers. However certain systems may require the application of an adhesion promoting primer prior to the application of the paint.

The table is a useful guide to determining the type of primer required for commonly used polymers.

Substrate Material	Recommended Primer	Comments
Polypropylene	ACT 710	Single coat air drying
Glass re-enforced polymers such as Noryl ,Nylon, polycarbonate, Acrylics, HIPS, and PVC	ACT 1006	Air drying solvent Single component water based.
Polyurethane Composites.	ACT 706	Two-component epoxy air-drying.

Base Coats offer colour and opacity. They can be applied as a single coat to a wide range of polymers or over-coated with clear top lacquers to increase chemical and wear resistance. There are two types of base coat available:

• Acrylic air-drying base coats are available in a full range of solid and metallic colours. However acrylic base coats only offer moderate levels of wear and abrasion resistance

Acrylic base coats can be over-coated with clear or tinted lacquers to provide increased chemical and wear resistance

• Two component (2-pack) polyurethane base coats are much more durable and can be applied as a single coat finish suitable for most applications.

Base coats can be categorised by the following properties.

Character / Property	Options Available	Comments
Reflectivity Opacity	Solid Metallic Pearlescent	Most base coats are available in the full range of BS and RAL colours. Colours can also be formulated to match customer requirements. Typically base coats come in three standard gloss levels, matt, semi matt and gloss. Metallic and Pearlescent paints are more expensive than solid colours. The cost of metallic paints depends critically on the quality and size of the metal flakes incorporated in the paint.
Diluents	Solvent Water	Most paint systems are available in either diluent. Solvent-based systems are faster drying and hence have lower processing costs. Adhesion to certain substrates is better with solvent systems.
Resin System	Acrylic	Acrylics are generally single component air-drying systems, offering moderate levels of chemical, wear and abrasion resistance. They can however be over coated with clear lacquers to provide long-term stability. Extremely reflective metallic finishes can be obtained with these paints.
	Polyurethane	Two component polyurethane base coats offer much higher levels of chemical and wear resistance. However it is difficult to achieve extremely reflective metallic finishes.
Texture	Fine Medium Coarse	Textured paints can be useful in concealing minor surface defects.

List of recommended base coat.

Reflectivity / Opacity	Diluent	Resin system	Base Coat Options	Comments
Solid	Solvent	Acrylic	ACT 712	Standard, available in BS and RAL colours.
			ACT 807	Customer specified colours could be formulated.
			ACT 707	Available with medium texture.
			ACT 823	Offers good inter-coat adhesion to soft feel topcoats.
Solid	Water	Acrylic	ACT 721	Standard, available in BS and RAL colours
Solid	Solvent	2-pack polyurethane	ACT 842	High build/opacity can be achieved. Excellent durability. Anti-graffiti, low smoke and toxic fume emission.
Solid	Water	2-pack polyurethane	ACT 722	Fully compliant.
Metallic	Solvent	Acrylic	ACT 805	Excellent range of aluminium, stainless steel and chrome effects available.
			ACT 804	Incorporating very fine pigments resulting in brilliant chrome effect.
			ACT 806	Suitable for over coating with soft feel top lacquer
Metallic	Water	Acrylic	ACT 839	Good adhesion to a wide range of plastics.
Metallic	Solvent	2-pack polyurethane	ACT 820	Available in a wide range of colours.
Metallic	Water	2-pack polyurethane	ACT832	Excellent durability and chemical resistance.
Pearlescent	Solvent	Acrylic	ACT 813	Pearlescent and two-tone colour effects.
Soft feel	Water	One pack	ACT 723	Soft touch without isocyanate
Soft feel	Water	2-pack	ACT 724	Excellent noise absorbance and tactile properties.

Clear Top Coats are usually applied over base coats to increase chemical, wear and abrasion resistance. They can also be engineered to provide the required gloss level.

Tinted Top Coats are applied over metallic base coats, metal substrates and electroplated components to provide brilliant anodised coloured finishes.

Clear soft feel top coats can be applied over suitable base coats.

Lacquer Type	Resin System	Diluent	Recommended System	Comments
Clear	2-pack polyurethane	Solvent	ACT 808	Available in matt, semi matt and gloss.
Clear	2-pack polyurethane	Water
Tinted	2-pack polyurethane	Solvent	ACT808B	Range of colours available.
Clear Soft feel	2-pack polyurethane	Solvent	ACT 817	Colourless matt finish, suitable as an over coat for opaque or metallic basecoats.

The quality and finish of the paint coating is essentially dependent on the substrate. The substrate must be clean and free of any grease, oil or mould release agents. Mouldings should also be free of sink-marks, scratches or blemishes as these can often be highlighted when high gloss finishes are applied.

Most paints are cured at 65-70°C, therefore substrates should be stable to 80-85°C.