A research project is underway to create a bidirectional reflectance and texture database of printed special effect colors. Such data is needed in the printing industry to determine the required measuring geometries characterizing the bidirectional reflectance distribution function (BRDF) and texture function (BTF), to develop quality measures for process control, and to simulate the prints' appearance on displays (soft proofing).Flexo printing was used to apply 28 special effect inks with three tonal values on a matt and glossy paper substrate. The inks were selected to cover a wide range of different pigment classes and with respect to their demand in the printing market. To allow for multiple usage scenarios the inks were printed on a black and white background and partly finished with a glossy varnish resulting in a total of 672 different samples. The patches were measured in a preliminary stage with the BYK-mac multi-angle spectrophotometer. Evaluations on the diversity of the samples in terms of selected appearance parameters such as color flop or sparkle intensity are determined based on these measurements. The data is provided on our website and will be supplemented with additional measurements performed by a gonio-imaging system.
Katharina Kehren, Philipp Urban, Edgar Dörsam, "Bidirectional Reflectance and Texture Database of Printed Special Effect Colors" in Proc. IS&T 19th Color and Imaging Conf., 2011, pp 316 - 321, https://doi.org/10.2352/CIC.2011.19.1.art00060