Artwork: Trim and Margins Explained
Trim and margins are fundamental to how printed pages are finished. Understanding the difference between them helps ensure your content is positioned correctly and nothing important is lost during production.
This guide explains what trim and margins are, how they affect your artwork, and how to set them up correctly for printed books and documents.
What is trim?
Trim refers to the final size of a printed page after it has been cut down from the larger sheet it is printed on.
When pages are printed, they are produced on oversized sheets and then trimmed to their finished dimensions. Because trimming is a mechanical process, very small variations are normal. Artwork should be prepared with this in mind.
The trim size should always match the final size of your book or document.
What are margins?
Margins are the blank areas inside the trimmed page where no critical content should be placed.
Margins provide:
Comfortable reading space
Visual balance on the page
Protection against trimming variation
Space near the spine for binding
Margins are especially important in books and bound documents.
Trim, bleed, and margins together
These three elements work as a system:
Bleed extends artwork beyond the trim edge
Trim is where the page is cut to final size
Margins keep important content safely inside the page
Understanding how they interact helps avoid common layout problems.
Recommended margin guidelines
While exact margin sizes can vary depending on format and binding, general guidance includes:
Inner (spine) margin: Larger than outer margins
Outer margin: Enough space for comfortable reading
Top margin: Allows for headers and page numbers
Bottom margin: Often slightly larger to balance the page
For most books, keeping key text and page numbers at least 10–15 mm away from the trim edge is a good starting point.
Spine and binding considerations
Binding type affects margin requirements.
For example:
Perfect bound and hardback books require wider inner margins to allow for the spine
Saddle-stitched booklets require less inner margin but still need safe spacing
Wiro and spiral bindings may require punch clearance
Always consider how the book will open and be read when setting margins.
Common trim and margin issues
Some of the most common problems we see include:
Text too close to the trim edge
Page numbers cut off or pushed into the spine
Inconsistent margins across pages
Margins not adjusted for binding type
Artwork aligned to the edge without bleed
These issues are avoidable with careful setup.
How to check your artwork
Before exporting your final PDF:
Confirm the page size matches the finished trim size
Check margins are consistent throughout the document
Ensure important content sits safely within the page
Review spreads where content crosses the spine
Taking a few minutes to review these details can prevent delays later.
If you’re unsure
If you’re not confident that your margins or trim are set correctly, you can still submit your files.
We’ll review the setup and flag anything that may cause issues before production begins.
Related guides
You may also find these articles helpful:
Supplying Print-Ready PDF Files
Bleed Explained
CMYK Colour Setup Explained
Binding Types and Margin Requirements