ISO 2814-1973 Comparison of Paints and varnishes of the same type and Color Paints contrast ratio (hiding power) is a standard published by the international standards organization to standardize the comparison of hiding power for paints of the same type and Color. The standard defines a measurement method of contrast ratio by measuring the reflectance of a sample of Spreader paints on a black and white substrate to assess its hiding power. The standard requires testing under specific Spreader Film thickness and environment conditions to ensure accuracy and comparability of results. The higher the contrast ratio, the stronger the hiding ability of paints. This standard provides an important reference for paints manufacturers and users, which helps to improve product mass and market competitiveness.