The use of dielectric and thus absorption-free coatings allows the production of spectroselective reflectors.

This example shows a mirror (trapezoidal glass substrate with edge lengths between 5 and 50 mm) for the wavelength range of 450 up to 660 nm with suppression of the UV and the IR range. Further requirements were the angle of incidence AOI = 45° and the compliance with the narrow tolerances concerning the colour values.

A correct reflexion measurement below 45° can only be realised with an absolute measurement ("VW" measuring principle).