bleed

A bleed is an extension of printed imagery beyond the intended trim edge of a finished sheet, typically 3 to 6 millimeters on each side. During finishing, this overprinted area is trimmed away. The bleed exists solely to compensate for the mechanical imprecision of cutting equipment, which cannot cut all sheets in a stack to exactly the same dimensions.

Without bleed, any slight misalignment during cutting will expose the white or unprinted substrate at the edge of the sheet, creating a visible fault. This is particularly damaging when photographs, colored backgrounds, or other imagery are meant to extend to the edge. With bleed, a small amount of off-register cutting still leaves printed material at the edge, making the defect invisible to the end user.

The bleed area must be specified when files are prepared for separation and plating. Digital design files include this extended canvas, and images intended to run edge-to-edge are positioned to extend into the bleed zone. Registration marks and other control elements may be placed in the bleed area or in the margin beyond it. Different print houses may specify slightly different bleed depths, so the printer's requirements must be confirmed before file preparation begins.

Bleed is critical in color process work. A four-color image that reaches the trim line on one color plate but falls short on another will show a colored fringe or white gap at the edge. All four separations must extend uniformly into the bleed to avoid this misregistration artifact. In litho and flexographic printing, where each color requires its own plate, consistent bleed on all plates is essential.

The term reflects its purpose: the image is allowed to bleed off the page rather than stop short. Bleed is universally expected in commercial printing and is built into most design and prepress workflows as standard practice.