Prepress printing — the important phase between design and production — is all about making sure that your digital files are formatted correctly and optimized for the best possible results when printing your book. Here's what aspiring authors need to know about having their books printed, and how to prepare to avoid errors, delays, color shifts, and print run rejections.
Getting your files ready for printing
In order to make sure you get the best possible results with your book printing, whether you're printing 100 copies or 10,000, your files need to meet strict specifications to go through the prepress process. The most common requirements include:
- Trim size + bleed: The PDF's page size must match the final trim dimensions plus bleed. Interior files require a 0.125" bleed on all sides.
- Single pages, not spreads: Files should consist of individual pages (and not spreads) to make sure that pages are numbered correctly
- Template-guided margins: Artwork and text must respect the margins outlined in the downloadable page templates.
- Accurate cover templates: Cover and dust jacket files must adhere exactly to the custom cover template — front, back, spine, and any dust jacket panels.
- Color mode & black composition: Files must be in CMYK (not RGB), with true black used instead of registration black.
- Font handling: All fonts must be embedded or converted to outlines to prevent substitution.
- Image quality: All images (including cover art) must be embedded at 300 dpi or higher.
- Clean PDFs: Files must be free of annotations, comments, or Acrobat notes.
Getting started with templates and file setup
First, download custom templates from OnPress via your Project Center. You'll find them divided into two categories:
- Cover templates: These include front and back panels, spine width, and dust jacket layouts (when applicable).
- Interior templates: These are single-page documents that are designed to be the correct trim size, complete with margin and bleed guidelines. These templates are designed to work with Adobe InDesign, Microsoft Word, QuarkXPress, and Apple Pages so that you can align your content to professional printing standards using your favorite program.
Bleed and safe margins
The bleed sounds a whole lot less painful than its name implies. It's essentially the extra artwork that extends beyond the trim edge (or bleeds over) which makes sure that you don't have any unintended white borders after your book is trimmed. At OnPress Book Printing, we require a 0.125"" bleed on all sides for any full-bleed elements.
Along the same lines are safe margins — these are areas inside the trim lines where all the critical text and images need to be to avoid being cut off. Both bleed and margins are defined in the downloadable page templates, so you don't need to be a print expert to know what goes where.
Color management and file setup
Consistent, vibrant color is one of the biggest benefits of working with a company that uses G7-certified presses. Our expertise in color management gives you bookstore-quality results you can rely on. We recommend submitting your files in CMYK mode. Although we can convert RGB images, it might create unexpected shifts in the colors. Use true black for deep, crisp blacks and avoid registration black, which can oversaturate the ink.
Our unique workflow means you don't need to add crop marks, registration marks, or color bars — you can leave those out when submitting your files.
Image resolution and proofing
High-resolution images are a must. All artwork, whether it's an interior illustration or your book cover design, needs to be at least 300 ppi at its intended print size. The prepress team looks at image resolution mechanically, and any files that are flagged for low resolution may not look good in print. To make sure the output is at the quality level you want, order a single book proof so that you can check the color fidelity via a physical sample before your full run begins.
Font and text handling
Embedding fonts or converting them to outlines in your PDF makes sure that the end result can be printed with your chosen typefaces and layouts. If fonts aren't embedded or converted, they could be substituted and create an end result that looks nothing like you intended. In order to guarantee that your text appears exactly the way it was designed, take the time to convert or embed the correct fonts.
Complimentary digital prepress review
At OnPress Book Printing, every order includes a free prepress review. During this review, our expert technicians closely examine your uploaded files to spot and flag any issues, including missing bleeds, color mode mismatches, or unembedded fonts, and walk you through how to correct the issues. This extra quality control step means you can order your books with confidence, knowing they'll look phenomenal.
Final proofs and approvals
Beyond the digital prepress review, we also offer other proofing options including PDF and hard-copy proofs so you can make sure that the corrections you want have been made. Reviewing proofs lets you catch any remaining issues, from slight color differences to layout shifts or missing elements. This step also helps you avoid costly reprints.
Getting started with the prepress process
We recommend downloading our free guide on how to prepare graphics files for book printing. The OnPress Help Center also provides detailed articles on bleed, templates, and export settings. Of course, if you need any help along the way, our Print Specialists are just a call or an email away and are ready to provide you with friendly, expert guidance.
As you can see, taking the time to understand and master the prepress process is your ticket to a smooth, easy book printing experience. By following our simple guidelines, taking advantage of templates, and correctly managing color and resolution, plus using the prepress review and proofing service, you can be confident that the end result will exceed your expectations. Contact us today to learn more!