Determining the Minimum Number of Measurements for Colour, Sparkle and Graininess in Gonio-Apparent Panels

In recent years there has been growing interest in characterising materials with unique visual effects, such as metallic, pearlescent, sparkle and graininess. Especially in sectors such as the automotive industry, cosmetics and consumer electronics, these effects are popular for their fascinating play of colour and visual appeal. Traditional colour measurement methods, which are generally sufficient for flat colours, fall short when measuring gonio-apparent materials; these behave differently under varying viewing angles and lighting conditions.

The Research

A team from the University of Alicante and the Technical University of Catalonia has investigated these measurement challenges. Their work, described in “The minimum number of measurements for colour sparkle and graininess characterisation in gonio-apparent panels,” published in Coloration Technology (Chorro et al., 2015), examines the precise measurement requirements for accurate characterisation of colour, sparkle and graininess.

Objectives and Methodology

The research aimed to verify whether gonio-apparent panels require more repeated measurements than panels with flat colours, with the hypothesis that special-effect pigments increase measurement variability. Using the BYK-mac multiangle spectrophotometer, which offers unique capabilities to measure colour, sparkle and graininess simultaneously from various angles, the researchers carried out twenty measurements at random positions on ninety samples with flat, metallic or pearlescent coatings.