How to add bleed and crop marks

Printers cut a stack of sheets at once, and the cut never lands exactly on the line. If the background stops at the edge of the design, any drift shows as a white sliver of paper. Bleed is the fix: the background and any images that touch an edge carry on past the cut, so the blade always goes through ink.

Three lines describe every printed piece:

• Trim: the finished size, where the paper is cut. A business card is 85 × 55 mm.
• Bleed: artwork extended beyond the trim on every side, usually 3 mm. The file for that card is 91 × 61 mm.
• Safe area: a margin inside the trim where text and logos stay, at least 3 mm. On the card that leaves 79 × 49 mm.

Bleed means more artwork, not more margin. A white border added around the design is exactly the sliver you were trying to avoid. And crop marks, if the printer wants them, are short lines drawn outside the bleed, in line with the trim, so the cutter can see where it is.

The sizes, worked out

Add twice the bleed to each side of the trim. Take twice the safe margin off for the area your text has to stay in.

The metric rows use 3 mm bleed and a 3 mm safe margin, the US rows 1/8 in for both. A photo that runs off the edge has to cover the bleed too, so check its pixels against the larger size (how to check an image is sharp enough to print).

Set it in your design app

The bleed belongs in the design file. Set it there, pull every background and edge image out to the bleed line, and the PDF export does the rest.

Canva has a Show print bleed setting and a Crop marks and bleed option when you download as PDF Print. Word and Google Docs have no bleed setting at all: there, the page size is the only lever, and the result has no trim information for the printer.

Check what the PDF has

A print PDF records its sizes as boxes. The MediaBox is the whole page, the BleedBox the artwork the printer should keep, the TrimBox the finished size. pdfinfo from Poppler (brew install poppler, apt install poppler-utils) prints them in points. Divide by 2.835 for millimetres.

A card exported without bleed:

pdfinfo -box card.pdf | grep -E 'Page size|Box'

Page size:       240.94 x 155.91 pts
MediaBox:            0.00     0.00   240.94   155.91
CropBox:             0.00     0.00   240.94   155.91
BleedBox:            0.00     0.00   240.94   155.91
TrimBox:             0.00     0.00   240.94   155.91
ArtBox:              0.00     0.00   240.94   155.91

240.94 × 155.91 points is 85 × 55 mm: the trim, and nothing outside it. The same card with 3 mm bleed and its trim marked (pdfinfo -box card-print.pdf):

Page size:       257.95 x 172.91 pts
MediaBox:            0.00     0.00   257.95   172.91
CropBox:             0.00     0.00   257.95   172.91
BleedBox:            0.00     0.00   257.95   172.91
TrimBox:             8.50     8.50   249.45   164.41
ArtBox:              0.00     0.00   257.95   172.91

The page is 91 × 61 mm, and the TrimBox sits 8.50 points (3 mm) in from every edge. That is a print-ready card.

pdfinfo fills in any box the file doesn't have with the page size, so all five lines being equal can also mean there is simply no TrimBox. To see whether one is really there, count them (qpdf, brew install qpdf, apt install qpdf):

qpdf --qdf --object-streams=disable card-bleed.pdf - | grep -a -c /TrimBox

0

Without a terminal, any PDF viewer gives you the page size (in Acrobat Reader, File › Properties). If it is the trim size, there is no bleed in the file. Zoom into each corner as well: the background should run right off the page.

The artwork is there, the trim isn't marked

Some apps export a page that is already 91 × 61 mm with the artwork running to the edge, but write no TrimBox. A printer whose spec only asks for the file at the bleed size will take it as it is. If their checks want the boxes, set them without touching anything else in the file. This short script uses pikepdf (pip install pikepdf, in a virtual environment if your system Python refuses) and sets the TrimBox the given number of millimetres in from every edge, on every page:

# set-boxes.py: python3 set-boxes.py in.pdf out.pdf 3
import sys, pikepdf
src, dst, bleed_mm = sys.argv[1], sys.argv[2], float(sys.argv[3])
b = bleed_mm * 72 / 25.4
with pikepdf.open(src) as pdf:
    for page in pdf.pages:
        x0, y0, x1, y1 = [float(v) for v in page.mediabox]
        page.bleedbox = [x0, y0, x1, y1]
        page.trimbox = [x0 + b, y0 + b, x1 - b, y1 - b]
    pdf.save(dst)

python3 set-boxes.py card-bleed.pdf card-print.pdf 3
pdfinfo -box card-print.pdf | grep -E 'Trim|Bleed'

BleedBox:            0.00     0.00   257.95   172.91
TrimBox:             8.50     8.50   249.45   164.41

It only adds the two boxes. Fonts, images, colours and a PDF/X output intent stay exactly as they were. Run it only on a file that really has the extra artwork; on an 85 × 55 mm page it would mark a 79 × 49 mm card.

Crop marks around an existing PDF

Ask before you add them. If the printer does want marks and your design app can't make them, Ghostscript can draw them around a PDF that already has its bleed. Save this as cropmarks.ps:

%!PS
% Centre each page of a PDF that already includes its bleed on a larger sheet,
% draw crop marks at the trim outside the bleed, and set TrimBox and BleedBox.
% Sizes in mm: TRIMW x TRIMH is the finished size, BLEED the bleed on each side.
% The sheet size comes from -dDEVICEWIDTHPOINTS/-dDEVICEHEIGHTPOINTS with -dFIXEDMEDIA.
/mm { 72 mul 25.4 div } def
/GAP 2 def                                  % gap between bleed edge and mark (mm)
/LEN 5 def                                  % mark length (mm)
/OFF BLEED GAP add def                      % trim edge to start of mark
currentpagedevice /PageSize get aload pop
  25.4 mul 72 div /SH exch def  25.4 mul 72 div /SW exch def   % sheet in mm
/MX SW TRIMW sub 2 div def                  % sheet edge to trim, left/right
/MY SH TRIMH sub 2 div def                  % sheet edge to trim, top/bottom
/corner {                                   % x y dx dy (outward)
  /dy exch def /dx exch def /y exch def /x exch def
  newpath x dx OFF mul add mm y mm moveto x dx OFF LEN add mul add mm y mm lineto stroke
  newpath x mm y dy OFF mul add mm moveto x mm y dy OFF LEN add mul add mm lineto stroke
} def
<< /PageOffset [ MX BLEED sub mm  MY BLEED sub mm ]
   /EndPage {
     exch pop 0 eq dup {
       gsave initgraphics
       MX BLEED sub mm neg  MY BLEED sub mm neg translate      % back to sheet corner
       [ /Separation /All /DeviceCMYK { dup dup dup } ] setcolorspace 1 setcolor
       0.25 setlinewidth
       MX MY -1 -1 corner             MX TRIMW add MY 1 -1 corner
       MX MY TRIMH add -1 1 corner    MX TRIMW add MY TRIMH add 1 1 corner
       grestore
       [ /TrimBox  [ MX mm  MY mm  MX TRIMW add mm  MY TRIMH add mm ]
         /BleedBox [ MX BLEED sub mm  MY BLEED sub mm
                     MX TRIMW add BLEED add mm  MY TRIMH add BLEED add mm ]
         /PAGE pdfmark
     } if
   }
>> setpagedevice

Then give it the trim size and bleed in millimetres, and a sheet in points that is at least 24 mm bigger than the trim each way. For the card that is 109 × 79 mm, or 309 × 224 points:

gs -o card-marks.pdf -sDEVICE=pdfwrite -dFIXEDMEDIA -dAutoRotatePages=/None \
   -dDEVICEWIDTHPOINTS=309 -dDEVICEHEIGHTPOINTS=224 \
   -dTRIMW=85 -dTRIMH=55 -dBLEED=3 cropmarks.ps -f card-print.pdf
pdfinfo -box card-marks.pdf | grep -E 'Page size|Trim|Bleed'

Page size:       309 x 224 pts
BleedBox:           25.52    25.54   283.48   198.46
TrimBox:            34.03    34.05   274.97   189.95

Rendered, the card sits in the middle of the sheet with eight 5 mm marks in line with its edges, each starting 2 mm outside the bleed. They are 0.25 pt lines in the registration colour, so they print on every plate. Swap the sheet size for -sPAPERSIZE=a4 to centre the card on an A4 proof instead.

When the PDF has no bleed at all

This is the hard case, and there is no clean command for it. The bleed is artwork that was never drawn, and no tool can know what should be there.

Scaling the page up doesn't work. An 85 × 55 mm card has to grow 7 % to reach 91 mm wide and 11 % to reach 61 mm tall. Stretch it by different amounts and circles turn into ovals and the type distorts. Scale it evenly by 11 % and it becomes 94.3 × 61 mm: the cut now goes through what used to be 4.2 mm in from the left and right edges, everything is 11 % bigger, and a line of text you placed 6 mm from the edge ends up 2 mm from the cut.

If every edge is one flat colour, you can paint the bleed in that colour. You need its exact values: open the design file or ask whoever made it. This Ghostscript script, saved as flatbleed.ps, centres each page on a larger one and fills the new margin:

%!PS
% Give a PDF whose edges are one flat colour a bleed: centre each page on a
% page BLEED mm larger all round, and paint the new margin in that colour.
% -dBLEED=3, the colour as CMYK from 0 to 1: -dC=0.85 -dM=0.35 -dY=0 -dK=0.1
% The new page size comes from -dDEVICEWIDTHPOINTS/-dDEVICEHEIGHTPOINTS with -dFIXEDMEDIA.
/mm { 72 mul 25.4 div } def
/re { 4 2 roll moveto 1 index 0 rlineto 0 exch rlineto neg 0 rlineto closepath } def
<< /PageOffset [ BLEED mm BLEED mm ]
   /EndPage {
     exch pop 0 eq dup {
       currentpagedevice /PageSize get aload pop /h exch def /w exch def
       /b BLEED mm def
       gsave initgraphics b neg dup translate
       C M Y K setcmykcolor
       newpath 0 0 w h re  b b w b 2 mul sub h b 2 mul sub re  eofill
       grestore
       [ /TrimBox [ b b w b sub h b sub ]  /BleedBox [ 0 0 w h ]  /PAGE pdfmark
     } if
   }
>> setpagedevice

The new page is the trim plus twice the bleed, in points (91 × 61 mm is 257.95 × 172.91):

gs -o card-flat-bleed.pdf -sDEVICE=pdfwrite -dFIXEDMEDIA -dAutoRotatePages=/None \
   -dDEVICEWIDTHPOINTS=257.95 -dDEVICEHEIGHTPOINTS=172.91 \
   -dBLEED=3 -dC=0.85 -dM=0.35 -dY=0 -dK=0.1 flatbleed.ps -f card-flat.pdf
pdfinfo -box card-flat-bleed.pdf | grep -E 'Page size|Trim'

Page size:       257.95 x 172.91 pts
TrimBox:             8.50     8.50   249.45   164.41

Rendered at 300 dpi, a 100-pixel square in the corner, which takes in both the new bleed and the original card, holds a single colour: no seam. Run the same command on a card with a yellow band along the bottom, though, and the bleed under the band comes out blue. The fill knows one colour, so it only works when the whole edge is that colour. It also has Ghostscript's rebuild caveat from the section above.

For anything else (a photo to the edge, a band of a second colour, a gradient), go back to the design file, set the bleed, extend the artwork and export again. If there is no design file, rebuild the layout from the PDF. Importing the PDF into an editor gives you its text, shapes and images as objects you can move, so the background can be pulled out to the bleed line. Check the text afterwards: a font the editor doesn't have gets substituted.

Popcorn sets up print documents with 3 mm bleed (1/8 in on US sizes), shows it as a red guide and the 3 mm safe margin as a green one, and has an 85 × 55 mm business card preset. Crop marks are off by default, with a 3 mm offset when you turn them on. Designing is free without an account; the print PDF needs a paid plan. Its own steps for importing a file are in Bring designs from PDF, Illustrator & Photoshop.

Before you send it

Bleed is one of the things a printer checks. Colour, image resolution and fonts are the others, and how to make a print-ready PDF goes through them in order, with converting RGB to CMYK and matching a Pantone colour in CMYK for the colour side.