Did you know that plates can be too white, too yellow or too black?
The colorimetric test makes sure that plates are the correct white and yellow (for backgrounds) and black (for digits).
The two elements of the colourimetry test, chromaticity and luminance, ensure that the colourimetry is correct with and without lighting.
How are plates tested?
Plates are tested in daylight conditions and readings taken at 45° by a specified machine. The results must fit a narrow range of limits to pass.
- Chromaticity measures the quality of colour independently of brightness, by checking the hue and saturation.
- Luminance measures the intensity of light emitted from a surface per unit area in a given direction.
What makes a fail?
Any of the readings fall outside of the narrow ranges for: