Abstract: A method for determining relative degrees of reflectance of a measurement surface, having the method steps of applying measurement radiation to the measurement surface, such that a measurement spot is produced on the management surface, moving the measurement spot along at least a first straight measurement spot path, over the measurement surface in accordance with a first path movement and along a second straight measurement spot path with a second path movement, recording a first and second image sets of a plurality of locally resolved images of the measurement surface during the first path movement and the second path movement. An evaluation is carried out at intersection points, whose location points on the management surface are defined by evaluation lines, wherein a first group of straight evaluation lines within the first measurement path region and a second group of straight evaluation lines within the second measurement path region are predefined and/or determined.

Abstract: A polymer opal material comprises a three dimensionally periodic arrangement of core particles in a matrix material and exhibits structural color via Bragg reflection. IN a process for manufacturing such a material, a sandwich structure is provided, of a precursor composite material held between first and second sandwiching layers. A relative shear strain of at least 10% is imposed on the precursor composite material by curling the sandwich structure around a roller. The shear strain is cycled, in order to promote the formation of the three dimensional periodic arrangement.