Colour Correction of Plastics |  |
Colour correction is a term used to describe the effect observed when low concentrations of ultramarine blue or violet pigments are added to media, such as plastics, which possess an inherent yellowish tint. Even the most effective whiteners for plastics, such as titanium dioxide, show faint degrees of yellowness. Ultramarines and manganese violet pigments, when added in trace quantities, counteract yellowness to produce a neutral, or ‘whiter than white’ shade.
Benefits of ultramarine pigments in colour correction:-
· Enhanced whites
· Excellent natural and artificial light performance
· Range of subtle tints
· Precise shade control
 Excellent Day and Artificial Light Performance
 Range of Subtle Tints
Colour correction is subjective and depends on the aesthetic preference of the observer. Ultramarine blue is used to produce ‘cold’ whites, whereas the violet pigments give ‘warmer’ tones. Very often, combinations of the blue and violet pigments are used to produce the desired effect. Where the initial degree of yellowness is pronounced, an increase in the ratio of violet to blue can significantly improve the final result.
Precise Shade Control
The exact pigment concentration needed to produce the desired level of colour correction depends on the initial degree of yellowness. Generally it is not necessary to use addition levels higher than 0.1% and often this figure is much lower. The moderate colour strength of ultramarine and manganese violet allows precise addition at various concentrations.
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