Bleed and Trim in Book Printing: What They Are and How to Set Them
Bleed and trim are essential for professional book printing. Set correctly, they prevent unwanted white edges and ensure colour or images run cleanly to the page edge.
What is bleed?
Bleed is the area of your design that extends past the final page size. Because sheets are printed larger and then cut down, a small overhang (typically 3 mm on all sides) lets the guillotine remove tiny shifts in trimming while keeping colour/images to the edge.
If there’s no bleed, even a slight trim variance can leave a thin white border on full-bleed photos or coloured backgrounds.
What is trim?
Trim is the final page size after cutting. Trim (and crop) marks show where the sheet will be cut so the finished book matches your selected size.
Using Microsoft Word (workaround)
Microsoft Word isn’t designed for professional bleeds and trim marks, but you can approximate bleed by making your page size slightly larger than the final trim and extending background elements to the new edge.
Set up a larger page in Word
- Go to Layout → Size → More Paper Sizes….
- Increase both width and height by 6 mm total (3 mm bleed on each side).
Example: For a 152 × 229 mm (6″×9″) book, set the page to 158 × 235 mm. - Place any background colours/images so they reach the outer edge of this larger page.
- Keep all text and critical graphics inside your safe margins (e.g., 15–20 mm from the final trim).
Export and handoff
- Export to PDF with fonts embedded (File → Save As → PDF or Export → PDF).
- Tell us your intended final trim size and that the file includes an extra 3 mm on all sides for bleed (we’ll handle trim/crop marks on press).
Common pitfalls to avoid
- Forgetting bleed on full-bleed photos or coloured backgrounds (leads to white slivers).
- Placing text too close to the trim (keep inside safe margins).
- Relying on Word for crop/trim marks—supply the oversize page, and we’ll manage marks in prepress.
