During application of special effect base paints, the effect particles align themselves exactly parallel to the surface in the paint layer while it is still liquid.
This means a particular thickness of the paint layer is required.
Because during painting the layer thickness in the transition zones reduces from normal to zero, the effect particles can no longer align themselves.
This leads to lighter, darker or cloudy zones.
If 1-component clear lacquer is sprayed before the base coat, this effect is prevented. An optically perfect transition will result.