How to prepare a print-ready PDF
Print PDFs follow different rules than the web or a screen. Here's a short rundown of what matters — and at each point you can check right away how your PDF is doing.
1. Colors in CMYK, not RGB
Print builds colors from four separations — cyan, magenta, yellow and black (CMYK). Create vector graphics and text directly in CMYK. Raster images can stay in RGB, but always with an embedded ICC profile (sRGB or AdobeRGB) so they convert correctly to print colors. Expect colors to shift on conversion.
In Preflighter: RGB objects are flagged by a banner and the preview converts them through ICC to print colors — just like the printer's RIP.
2. Spot colors (Pantone) only when needed
Keep a spot color in your data only when it should print as a separate plate (e.g. gold, a die-cut line, varnish). Convert everything else to process (CMYK). For the same spot color, use one consistent name and definition.
In Preflighter: the Plates panel shows each spot color as its own plate — the ones you don't need stand out at a glance.
3. Overprint — watch out for white
The most common trap: white text or an object with overprint turned on disappears completely in print. White must never overprint. Small black text (up to about 12 pt), on the other hand, should overprint so the paper doesn't show through. Make large black areas "rich black" (e.g. 100% K + 40% C) with overprint off.
In Preflighter: the Overprint comparison mode shows side by side what disappears or appears with overprint.
4. Ink coverage (TAC)
The sum of all inks in one spot (Total Area Coverage) must not exceed the stock's limit — around 300% for offset on coated paper. Above the limit, ink dries poorly, smudges and shows through.
In Preflighter: the Ink coverage (TAC) mode highlights areas over your chosen limit.
5. Output intent (the paper's ICC profile)
Embed an output intent matching the paper: Coated FOGRA39 (ISO Coated v2) for coated stock, Uncoated FOGRA29 (ISO Uncoated) for uncoated offset paper. It defines how the colors in your data should be interpreted.
In Preflighter: the Output intent panel shows the profile embedded in the PDF (or matched by name).
6. Bleed and format (PDF boxes)
The trim size of the finished piece is set by the TrimBox. Objects reaching the edge must extend 3 mm of bleed (the BleedBox), otherwise trimming risks white slivers. Keep important content at least 3–4 mm from the edge (safe zone).
In Preflighter: the PDF box switch and box outlines show the TrimBox and BleedBox and whether the bleed really fits.
7. Image resolution
For offset use 300 dpi at final size (for laser the minimum is around 150 dpi). Don't use heavy JPEG compression — it creates visible artifacts that won't disappear in print.
In Preflighter: the Images inspection lists the resolution and color space of each image.
8. Embedded fonts
All fonts must be embedded in the PDF, or the RIP will substitute them and the text will break (different font, different line breaks). Always embed fonts on export, or convert problematic text to outlines.
In Preflighter: the Fonts inspection flags non-embedded fonts.
9. File format: PDF/X
The safest option is to export straight to the PDF/X-4 standard (modern, supports transparency and ICC profiles) or PDF/X-1a (conservative, everything flattened to CMYK). These standards make sure the PDF has everything needed for print and nothing is missing.