Add bleed and trim marks to a PDF

The same furniture Illustrator and InDesign put around an exported page, at the same sizes — because that is what a printer recognises, and what your designer would have sent them. All of it is drawn as PDF vector, so a 0.25pt hairline stays a hairline whether the artwork is 150dpi or 600dpi.

• Trim marks — the corner lines the guillotine is set to. They stop short of the corner so the cut line is implied rather than drawn over.
• Registration marks — the bullseye targets a press operator lines the plates up on.
• Colour bars — a tint strip for spotting a press drifting across a run.
• Page information — filename, page number and the time it was exported, along the bottom margin.

The file also carries real /TrimBox, /BleedBox and /ArtBox entries. That matters more than it sounds: it means prepress software reads your finished size as a fact from the file, instead of guessing it from where the marks happen to sit.

Two things worth being straight about. The colour bar is an RGB stand-in for the process inks — useful for spotting drift, but not a calibrated CMYK control strip, and there is no colour management here: if your artwork is RGB, the PDF is RGB. And the mark offset is measured from the trim, not the bleed, so with a bleed set the first couple of points of each mark sit on top of bled artwork. That is correct — everything outside the cut line is offcut either way.

Guillotines are accurate to about a millimetre, not to zero. If your background stops exactly at the finished size, a fractional shift in the cut leaves a white sliver down one edge — and on a stack of 500, some will have it and some will not.

Bleed is simply artwork extended past the trim line so there is something to cut into. Most Australian trade printers want 3mm on every edge, with anything important kept at least 3mm inside the trim.

• Trim — the finished size. A business card trims to 90 × 55mm.
• Bleed — 3mm of extra background beyond that, so 96 × 61mm supplied.
• Safe area — 3mm inside the trim. Nothing you care about goes closer than this.

The most common rejection we see is not missing bleed — it is text too close to the trim. A file with no bleed can usually be rescued by scaling. Text 1mm from the edge cannot, because there is nowhere for it to go.