ANALYSIS OF THE INTERPLAY OF THE PIGMENT SHAPE AND SIZE ON SPARKLE DETECTION DISTANCE BY DESIGN OF EXPERIMENTS (PO33, Pages 345-350)

There are numerous factors that can influence when the sparkle texture effect is perceived such as the size, shape, thickness and orientation of the special-effect pigment, its chemical composition and number and thickness of layers, pigment concentration, hue, chroma and lightness of the coating sample, etc. In this work we will focus on the type (morphology) and the size (D50) of the pigment, and how they affect these variables when sparkle (glint or glitter) is visually detected. The first hypothesis of this work is to study what kind of pigment shape is detected at a longer distance for the observer, and the second one is to evaluate how the pigment size influences on the sparkle detection distance. Subsequently a comparison of the results of the visual experiment with the instrumental values provided by the BYK-mac multi-angle spectrophotometer is performed, to study whether there is a correlation between what predicts the commercial device and our eyes perceive.