Although gloss is one of the most important optical properties of a glazed tableware article and contributes greatly to its market value, it is often not measured quantitatively, and the tableware industry relies more on visual judgements which always carry the risk of producing unreliable and unreproducible results. In this article gloss measurements carried out on hard-paste porcelain with commercial gloss meters operating under the TAPPI 480T and ASTM D523 norm are described. The aim is to develop a standard measurement technique for Imerys Tableware to quantify the gloss of their porcelain glazes. The results are compared with a visual pair comparison test performed by 21 observers. Good results were found between those obtained from ASTM D523 measurements at 20° (for high-gloss samples) and 60° (for matte glazes) and the visual ranking exercise. To obtain data with a sufficiently high resolution, it is important to choose a measurement method with small convergence and acceptance angles and the suitable specular measurement angle.
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