GB/T 12911-2025 "Paper and board — Determination of ink absorbency" is applicable to the determination of the ink absorption performance of various types of paper and paperboard, serving as a key standard for quality control in the papermaking and printing industries. It specifies multiple testing methods, such as the quantitative method and the printability tester method, and clarifies requirements for standard temperature and humidity environments, sample conditioning, and ink selection standards. The standard covers core aspects including sample preparation, application/transfer operations, mass or density measurement, and result calculation. It directly relates to the color saturation and drying speed of printed products, providing technical support for matching products with printing processes.