Cause
There is no single cause, the defect may result from a number of factors:
- Use of differing or incorrect materials.
- Inadequate mixing of the paint.
- Fading due to weathering or exposure.
- Incorrect application.
- Metameric distortion (Colour variation in differing light).
- Incorrect colour choice or use of the wrong variant of the colour.
- Insufficient film build of topcoat - full opacity not achieved.
Prevention
- Use only recommended materials
- Ensure that the paint is mixed thoroughly and correctly.
- Protect surface in storage.
- Apply materials correctly, use correct spraying technique.
- Before painting the surface, spray a test panel with the paint to be used and compare with the original at different angles and in differing light.
- Use the manufacturers colour system to select the correct colour and variant.
Rectification
Flat down the surface and repaint using the correct colour and variant