Paper grade is a numerical and descriptive system used to indicate the contrast level of photographic printing paper. Typical grades range from 0 (soft) for low-contrast prints, 1 (soft), 2 (normal), 3 (hard), 4–5 (very hard), up to 6 (ultra hard) for high-contrast images.
It is important to note that similar grade numbers from different manufacturers may not produce identical results, as each brand has its own contrast characteristics. Understanding paper grade allows photographers to select the appropriate paper for their intended tonal range and artistic effect, ensuring precise control over print contrast in the darkroom.