Measuring sparkle of effect coatings

28th Session, Manchester/UK, June 28 - July 4, 2015; http://session2015.cie.co.at/When effect coatings are illuminated by a highly directional source, as the sun in a clear day, a non-uniform texture is observed consisting of very bright sports distributed on a dark surround. This effect is usually known as sparkle, glitter or glint. The present state of imaging technology allows sparkle to be measured, but to date the only commercially-available instrument to quantify sparkle is BYK-mac. This instrument measures some sparkle parameters which are supposedly correlated with the visual experience. However, the measurands corresponding to these parameters are not clearly defined and they cannot be measured by any other instrument. In this contribution, we describe well-defined and traceable quantities to characterize sparkle and the experimental procedure. Sparkle measurements on three samples will be shown.Peer Reviewe