The brochure was signed off on Tuesday, sent to the printer on Wednesday, and rejected on Thursday morning: fonts not embedded, images at 96 dpi, no bleed, RGB colour. The launch is on Monday.
Nearly every print rejection comes from the same short list of problems, and all of them are checkable before the file leaves your office. This guide covers what makes a PDF print-ready, how to run a preflight check yourself, what the PDF/X standards are for, and what to ask your printer before you start designing.
What "Print-Ready" Actually Means
A print-ready PDF is one a printer can output without contacting you. It contains everything needed to reproduce the document exactly as intended, with no external dependencies and no ambiguity.
In practice that means six things:
- Fonts embedded, so the printer's system does not substitute anything.
- Images at adequate resolution for the size they appear.
- Colour defined in the right space, usually CMYK with spot colours specified where used.
- Bleed on anything running to the page edge.
- Safe margins, with nothing critical near the trim.
- Transparency handled correctly for the printer's workflow.
Screen PDFs and print PDFs are genuinely different outputs from the same source, which is why a file that looks perfect on a monitor can be unusable on press.
The Six Requirements in Detail
Resolution: the number that matters
The working standard for commercial print is 300 dpi at final placed size. That qualifier does most of the work.
A 1,200-pixel-wide image placed at 4cm is comfortably above 300 dpi. The same image stretched across a 20cm page is roughly 150 dpi and will look soft. Scaling an image up in the layout does not add detail — it spreads the existing pixels further apart.
Two common sources of trouble. Web images are typically 72 to 96 dpi and are almost never suitable for print at any meaningful size. And logos pulled from a website are raster files; for print they should be vector, which is covered in professional vector tracing.
Line art and scanned signatures are the exception in the other direction — they benefit from considerably higher resolution, often 600 to 1200 dpi, because the eye is unforgiving about jagged edges on a hard black line.
Colour: RGB, CMYK and spot
Screens emit light and use RGB. Presses lay down ink and use CMYK. The two describe overlapping but different ranges of colour, and some RGB values simply cannot be reproduced in CMYK — bright oranges, vivid greens and electric blues are the usual casualties.
What this means practically:
- Convert to CMYK deliberately, rather than letting the printer's system do it automatically. An automatic conversion may shift your brand colour.
- Specify spot colours where exact matching matters — brand colours on packaging, signage and stationery. A Pantone reference removes the ambiguity entirely.
- Expect some shift between screen and print, and check a proof rather than trusting a monitor.
- Watch rich black. Large black areas usually need a rich black build rather than 100% K alone, which prints as a slightly washed grey. Small text, though, should stay 100% K only — rich black on body text causes registration problems and fuzzy edges.
- Avoid total ink coverage that is too high. Printers specify a maximum; exceeding it causes ink not to dry properly and can offset onto the next sheet.
Bleed, trim and safe area
Three concepts that account for a large share of reprints.
Trim is the finished size of the printed piece.
Bleed is the extra image area extending beyond the trim, so that when the guillotine cuts slightly off — and it always does, by a fraction of a millimetre — no white sliver appears at the edge. The standard allowance is 3mm on each side in most markets; some printers ask for more on large-format work.
Safe area is the inner margin where nothing important should sit. Text or logos placed 1mm from the trim will look off-centre on some copies and be clipped on others. Keeping critical content at least 3 to 5mm inside the trim is the usual guidance.
The practical error is designing to the finished size and adding bleed at export. Background images have to actually extend past the trim — if they stop at the page edge, exporting with bleed produces a white strip.
Fonts
The single most common rejection. A font that is not embedded will be substituted, and substitution changes character widths, which reflows every line of text in the document.
- Embed everything, including fonts used inside placed logos and graphics.
- Check licensing. Some font licences restrict embedding, and this surfaces at export rather than at purchase.
- Consider outlining type for small jobs such as logos and signage, which converts letters to shapes and removes the question entirely. Do not outline body text — it prevents any later correction and can affect how small type renders.
- Avoid fake bold and italic, applied by the software rather than by using a real bold or italic weight. These often reproduce poorly.
The PDF/X Standards
If your printer asks for "PDF/X-1a" or "PDF/X-4", they are asking for a file that conforms to a specific ISO specification.
PDF/X is defined by the ISO 15930 family, developed specifically for prepress data exchange. Conforming files must have fonts embedded, colour properly defined, and bleed and trim boxes specified — the standard enforces exactly the checks described above.
The two you will encounter most often:
- PDF/X-1a — everything converted to CMYK and spot colours, transparency flattened. Conservative and highly predictable, which is why many printers still prefer it.
- PDF/X-4 — supports live transparency and colour-managed workflows, so it suits modern equipment and avoids flattening artefacts.
Ask which your printer wants rather than choosing. Exporting to the wrong standard is not usually fatal, but exporting to a standard your printer's workflow does not handle can produce unexpected results.
The Specification to Request
Every printer has a spec sheet, and asking for it before you design removes almost every problem in this article. What to ask:
| Ask about | Why it matters | Typical answer |
|---|---|---|
| Required PDF standard | Determines export settings | PDF/X-1a or PDF/X-4 |
| Bleed allowance | Must be built into the artwork | 3mm each side |
| Safe margin | Keeps content off the trim | 3–5mm inside |
| Colour profile | Affects CMYK conversion | Varies by press and stock |
| Maximum ink coverage | Prevents drying and offsetting problems | Often around 280–300% |
| Pages or spreads | Changes how you export | Usually single pages |
| Minimum image resolution | Sets your asset requirements | 300 dpi at placed size |
| Proof available | Last chance to catch colour issues | Digital or wet proof |
Large-format work — banners, vehicle graphics, exhibition panels — has different rules again. Viewing distance means lower resolution is acceptable, sometimes considerably lower, but bleed requirements are often larger and finishing allowances for eyelets, hems and pole pockets have to be designed in. Ask rather than assume.
Preflight: Checking Before You Send
Preflight is the systematic check that a file meets print requirements. Professional PDF tools include a preflight function; many printers also offer one.
A workable manual checklist if you do not have preflight tools:
- Document properties → Fonts. Every font should say "Embedded" or "Embedded Subset".
- Check image resolution, either through a preflight report or by checking your source images against their placed size.
- Check colour space. Anything showing as RGB needs converting or confirming with the printer.
- Check page size and bleed. The PDF page should be the trim size plus bleed on all sides.
- Confirm page count and order, including blank pages where the binding requires them.
- Check all pages are the same size and orientation unless deliberately mixed.
- Zoom to 400% on images and logos to check for softness or artefacts.
- Print a copy on an office printer. Crude, but it catches missing elements, wrong pages and obvious colour problems.
- Read it one last time. Typos are far more expensive after five thousand copies.
Single Pages or Spreads?
A source of confusion on anything bound. Most printers want single pages in reading order — they impose the pages onto press sheets themselves. Supplying reader's spreads, where pages 2 and 3 appear side by side on one sheet, forces them to split your file, and sometimes they cannot.
This is worth asking about explicitly, because assumptions differ between printers and getting it wrong means re-exporting at the worst moment.
Common Mistakes
- Exporting a screen PDF for print, compressed and in RGB.
- Designing to trim size with no bleed area on the artwork.
- Using web images, which are typically 72 to 96 dpi.
- A raster logo where vector was needed.
- Fonts not embedded, or embedded inside placed files but not the document.
- Rich black on small text, causing fuzzy edges.
- Critical content too near the trim.
- Spot colours left in a CMYK-only job, which can add an unexpected plate and cost.
- Hyperlinks and form fields left in a print file — harmless usually, but a sign the export preset was wrong.
- No proof requested on a job large enough to matter.
Fixing a File That Is Already Wrong
When the source file is gone and only the PDF exists, some things can be corrected in the PDF and some cannot.
Usually fixable: converting colour to CMYK, embedding fonts where the full font is available, adding bleed where the artwork extends far enough, flattening transparency, adjusting page boxes, and correcting page order or size consistency.
Not fixable: low-resolution images. No process adds detail that was never captured, and upscaling produces softness rather than sharpness. If the images are too low-resolution, they must be replaced from originals.
That distinction is worth establishing early, because it determines whether the job is a repair or a rebuild. The wider considerations are covered in professional PDF editing.
Conclusion
Print-ready is a specification, not a quality judgement. Fonts embedded, images at 300 dpi at placed size, colour in CMYK with spot colours defined, 3mm bleed, safe margins, and the PDF standard your printer asked for.
The most useful habit is getting the printer's specification before you start designing rather than before you send. Almost everything on the checklist is easier to build in than to retrofit.
Getting Files Prepared for Print
SBTEXMEDIA prepares print-ready files for businesses, agencies, publishers, retailers and organisations — colour conversion with spot colours defined, font embedding, bleed and page box setup, transparency handling, preflight checking against your printer's specification, and export to the PDF/X standard requested. Existing files can be corrected where correction is possible, with an honest assessment upfront when images need replacing rather than fixing.
Related work on graphic design, vector artwork for print and signage and screen versions of print documents is handled by the same team.
You can see examples on the portfolio, browse the full range of services, or send your file and your printer's specification for a fixed quote and a delivery date before work begins. More guides are on the SBTEXMEDIA blog.
