Coating coverage is different with different coating formulas. The gradient of the image matrix can well be used to explain factors to some extent. During the course of analysis of coating coverage, it is found that high kaolin with aspect ratio is helpful to improve coating coverage. In addition, ordinary kaolin, mixed with calcined kaolin properly can improve the coating coverage. According to the result of lightweight coated (LWC) paper from the experiments, Burnout-treatment can be used to determine the mass distribution of the coating layer.