Bleed

Commercial presses print many cards on large sheets that are then cut to size. Even with precision cutting equipment, there is a small tolerance of variance — the cut line can land slightly inside or outside the intended edge. If your background color or image stops exactly at the trim line and the blade runs even a hair inside it, you get a thin white sliver along one side of your finished card. Adding bleed means extending any background artwork, photos, or color fills 0.125" past where you expect the card to be cut. The printer's software then uses that buffer to ensure a clean, edge-to-edge result regardless of small cutting variance. Anything you don't want trimmed off — text, logos, faces, key design elements — must stay inside the safe zone, which is typically 0.125" inside the trim line on every side.