Bleed, safe margin and trim line, explained

Every file you send to print has three lines. The trim line is the finished size. The bleed is a band, usually 3 mm, outside it, where the background keeps going. The safe margin is a band inside, at least 5 mm, where no text or logo goes. Skip the bleed and you get white edges; skip the safe margin and you get letters cut off.

Why nobody cuts exactly on the line

Printed sheets aren't trimmed one at a time. They're cut in stacks, quickly, on a guillotine or a cutting machine. Vistaprint's help page says it plainly: because cutting happens fast and in large batches, small variations occur. The blade can land a little inside or a little outside the line you drew.

All three lines exist because of that variation. Bleed covers the cut drifting outward. The safe margin covers it drifting inward.

The trim line: the finished size

This is the size you hold in your hand at the end. For an A5 flyer, the trim line is 148 × 210 mm, as the ISO 216 standard defines A5. For a business card, it's whatever size the printer asks for.

The trim line doesn't print on the product. In the PDF it only shows up as crop marks: short lines in the corners, outside the page, that show the operator where to cut.

Bleed: 3 mm outside

Anything that touches the edge of the page has to run past it: a colored background, a photo, a pattern, a stripe. University of Bristol Print Services recommends 3 mm of bleed on all sides. It's also our starting point for standard formats.

So for an A5 flyer, the file is 154 × 216 mm: an extra 3 mm on each of the four sides. Everything in those 3 mm gets thrown away when the sheet is trimmed, but if the blade drifts a little, there's still background under it, not white paper.

Two mistakes that come up a lot:

• The background stops exactly at the trim line. It looks perfect on screen. After trimming, there's a thin white sliver on one or two sides.
• The bleed is a white border. A white band around the file isn't bleed. It's exactly the problem bleed was supposed to solve.

Large formats, special materials and folded pieces may need more than 3 mm. Ask the printer before you start the file, not after.

The safe margin: keep text away from the edge

Inside the trim line there's a second band where nothing important goes: text, logo, phone number, QR code. Bristol's guide recommends keeping text and logos at least 5 mm from the edge.

What happens without it? If the phone number sits 1 mm from the edge and the cut comes in 1 mm, the last digit is gone. On a business card, that means binning the whole run.

There's a subtler case too: thin borders near the edge. A 2 mm frame around a business card looks great on screen. If the cut shifts by 0.5 mm, the frame comes out thicker on one side and thinner on the other, and the eye catches it immediately. If you want a frame, make it wide and run it into the bleed, or drop it.

How to set them up in the file

1. Create the document at the finished size (the trim line), not the size with bleed.
2. Set a 3 mm bleed in the document settings. Layout apps show it as a line outside the page.
3. Pull backgrounds and edge-touching photos out to the bleed line.
4. Add guides 5 mm inside the edge and keep text within them.
5. Export a PDF with bleed and crop marks included. Bristol explicitly asks for both in any PDF sent to print.

A print file has two more requirements, which we covered separately: CMYK colors instead of RGB and a vector logo.

When you send us a file for business cards or flyers, we check the lines before printing and tell you if anything sits too close to the edge.