Specialty Finishes and Custom Painting
What the exam tests
This domain covers specialty and custom finishes: graphic layout, masking, candy and pearl effects, matte and satin clears, textured finishes, airbrushing, and intercoat compatibility. Questions test whether you can plan a multi-stage finish and protect the effect without destroying it.
Core rules
- Plan the design before spraying: measure, centre, and mark the layout; use fine-line tape and masking paper that resist solvent; burnish edges to prevent bleed.
- Build custom effects in the correct order. A typical candy job uses a base colour, a metallic or pearl ground coat, a uniform candy coat, and clear. Candy is transparent; uneven passes show as stripes.
- Use an intercoat clear where the system requires it to protect a base or graphic before masking or adding another effect.
- Keep gun distance, speed, and overlap consistent across the panel. Candy and pearl are unforgiving of uneven film build.
- Matte and satin clears require the specified reduction, pressure, and film build. Do not polish them unless the product allows it; polishing changes gloss.
- Test compatibility of special-effect products, vinyl, and adhesives on a test panel. Some graphics require a specific clear or a waterborne system.
- Document custom layers and products so a repair can be matched later.
Worked example
A technician sprays candy apple over a gold base. The first coat looks streaky because the gun was held closer on one side of the panel. The correct reasoning: candy is a transparent tinted coat, so film thickness controls colour strength. The fix is to let it flash, maintain a consistent distance and overlap, and build the colour in uniform coats. Sanding the candy to even it out is risky because it can cut through the effect.
Traps that cost marks
- Trying to fix candy streaks with a heavier coat instead of uniform passes.
- Using aggressive tape on a fresh effect.
- Polishing a matte clear and expecting the original gloss.
- Skipping a compatibility test for special-effect products.