underprinting

Underprinting is a printing practice in which a base layer of ink is printed beneath one or more subsequent colors. It is used to improve color opacity, tonal balance, and legibility on substrates where the paper color or transparency would otherwise affect the final result. The technique is commonly associated with offset lithography and can be applied in both prepress and on-press workflows.

Common implementations include white underprints on colored or transparent stocks to block show-through, and neutral or tinted underprints (such as gray) to balance color and provide a stable foundation for the top colors. Underprinting is particularly useful when printing on dark or vibrant backgrounds, when precise color reproduction is needed, or when a printed image must maintain consistency despite substrate variation.

Underprinting is related to, and sometimes opposite of, overprinting. Overprinting prints colors on top of underlying inks, which can create color effects or ensure that colors do not knock out underlying layers. Underprinting, in contrast, deliberately places the base layer first so that it influences the appearance of the layers printed above. In design software and prepress, underprint settings can control how elements interact for trapping and registration, helping to prevent white gaps caused by misregistration or substrate transparency.

Limitations include increased ink usage, longer drying times, and added complexity in color management. Not all jobs require underprinting, and improper use can distort color or raise production costs. Proper assessment of substrate, ink behavior, and press capabilities is essential when considering underprinting.