bleed
Also known as: bleed area · full bleed
Bleed is extra artwork that extends 0.125 inches past every edge of the final trim line, so the printer can cut your piece without leaving white slivers.
Bleed exists because no production cutter is perfectly aligned — every printed piece shifts up to about 1/16″ during trimming. If your background colour or image stops exactly at the trim line, that drift leaves an unprinted white edge. Extending the artwork an extra 0.125″ on each side gives the cutter room to wander while keeping the visible edge of the print fully covered. When you export from your design tool, set the document size to your final size PLUS 0.25″ (0.125″ × 2) and place your bleed there.