Areas of the surface with a differing texture or degree of gloss, surrounded by clearly defined boundary or contour lines.
Cause
• Too coarse of sandpaper used
• Improper thinner used
• Undercoats not thoroughly cured before applying color
• High film build of undercoats
• Improper cleaning
Prevention
• Use appropriate grit sandpaper being careful not to sand through soft or sensitive substrates
• Use appropriate thinner for spray environment
• Do not apply excessive film build of undercoats
• Use compatible paint system
Rectification
• Ensure undercoats are thoroughly cured before applying topcoat
• Sand the affected area and seal before applying topcoat
