Standardized Laboratory Methods for Evaluating Matte Print Coating Burnishing
Standard laboratory burnish evaluation uses controlled sled friction and 60-degree delta gloss measurements to quantify matte coating asperity degradation.
Delta Gloss
Surface Divergence
Quality control metrics of this type determine the numeric difference in luster between printed and unprinted regions of a paper substrate. The delta gloss represents the variance between the specular reflectance of the cured ink film and that of the base sheet. High values indicate a clear distinction that often correlates with perceived print quality.
Measurement Delta
Optical testing gauges the reflectance at a sixty degree angle on both the unvarnished paperboard and the fully dried print area. This evaluation subtracts the lower value from the higher value to calculate the final differential. When a matte coating is applied to a high gloss board, the resulting value is intentionally high.
Applying a glossy ink to a matte board yields a similar contrast. The printed surface reflects more light than the dull substrate, which makes the image appear prominent.
Printing Variance
Achieving the correct contrast prevents the printed graphic from blending into the background. Coated sheets with uniform surface energy allow for controlled ink absorption and stable reflectance. This value holds no meaning for fully varnished sheets where the entire surface is sealed with a single protective layer.
Extreme roughness in the base paperboard can scatter the light and render the optical measurement inaccurate.