Sending a PDF to a print shop is different from printing at home or at the office. Professional print equipment is more precise and more unforgiving โ a file that prints acceptably on a desktop printer may come back from a print shop with color shifts, clipped edges, or font problems. Most of these issues are preventable if you prepare the file correctly before submitting.
Ask the Print Shop for Their File Specs First
Before you prepare anything, contact the print shop and ask for their PDF specifications. Different shops have different requirements: some want PDF/X-1a, others accept PDF/X-4, some have specific resolution minimums, and they all have opinions about bleed and color profiles. Taking five minutes to get their spec sheet before you start saves you from remaking the file after the fact.
If you're using an online print service rather than a local shop, their upload page usually lists technical requirements. Read these before uploading โ they'll tell you exactly what page size, resolution, color mode, and bleed settings they expect.
Resolution: Minimum 300 DPI for Images
Images in a print-ready PDF need to be at least 300 DPI at the final print size. This is the standard minimum for offset and digital printing to appear sharp. Images that look fine on screen at 72-96 DPI will print soft and pixelated at 300 DPI if they don't actually contain that resolution.
Upscaling a low-resolution image doesn't add detail โ it just stretches existing pixels. If your image is 150 DPI at the intended print size, you need a higher-resolution version of the image, not a resize in the file. Check image resolution in your design software before exporting, not by looking at the on-screen appearance.
Color Mode: CMYK vs RGB
Screens display color in RGB (red, green, blue). Professional printing uses CMYK (cyan, magenta, yellow, black). When an RGB file is sent to a CMYK printer, the press operator's equipment converts the colors automatically โ but automatic conversion doesn't always produce what you expected. Bright RGB colors in particular can shift significantly when converted to CMYK, because the CMYK gamut can't reproduce every RGB color.
For professional print jobs where color accuracy matters, convert your document to CMYK in your design software before exporting the PDF. This lets you see the color shift on screen before committing to print. Many print shops specify CMYK as a requirement โ an RGB file may be rejected or converted without preview.
For simple text documents, black-and-white, or situations where you're printing at a quick-print shop that does digital printing, RGB is usually fine โ digital presses handle the conversion automatically and the results are predictable.
Bleed and Trim Marks
Bleed is the area of color or image that extends beyond the intended trim edge of the page. It exists because cutting is imprecise โ a 1-2mm cut variation either way means that without bleed, you end up with a thin white sliver at the edge of a page that was supposed to have color to the edge. Industry standard bleed is 3mm (or 0.125 inches) on all sides.
If your design has color, images, or any element that should go to the page edge, extend those elements 3mm beyond the trim size in your design software and enable bleed in the PDF export settings. The exported PDF will be slightly larger than the finished piece โ that's correct. The print shop trims off the bleed after printing.
Trim marks (also called crop marks) show the print shop exactly where to cut. Most professional PDF export presets include them automatically when bleed is set. Some print shops prefer files without crop marks and handle trimming themselves โ check their preference before adding them.
Fonts Must Be Embedded
Every font used in a print-ready PDF must be embedded in the file. A print shop's system doesn't have every font installed โ if a font isn't embedded and isn't on their system, it gets substituted with a default, which changes the layout and appearance of your document. This is one of the most common causes of print jobs coming back looking nothing like the original.
Modern PDF export presets from professional design software embed fonts automatically. Check the exported file's properties under the Fonts tab to confirm all fonts show as "Embedded" or "Embedded Subset." If any show as not embedded, go back to your application's PDF export settings and enable font embedding.
Final File Size and Delivery
Print-ready PDFs can be large โ 50-200MB for a multi-page document with high-resolution images is normal and expected. Don't run a print-ready file through a PDF Compression tool before sending to the print shop. Compression reduces image resolution and can undo the careful resolution settings you put in place. Send the full-quality file.
For delivery, most print shops accept large files via their upload portal, WeTransfer, Dropbox, or Google Drive link. Emailing a 100MB PDF is not reliable โ use a file transfer service. Confirm receipt with the print shop and ask them to flag any file issues before they go to press.