Preparing your file for the printer: bleed, CMYK, PDF/X

Independent guide, updated on 1 November 2026. Practices vary from one workshop to another: have your printer confirm the values.

A well-prepared file means a print that matches what you see on screen, with no back-and-forth with the printer and no delay. This page explains the basic concepts, then what to check for each family of products. If in doubt, ask the printer for their specifications or template: their instructions always take precedence over a general guide.

The essentials

Trimmed size, bleed and safe area

• Trimmed size: the dimensions of the printed item after cutting (for example 85 × 55 mm for a business card).
• Bleed: a guillotine never cuts exactly to a tenth of a millimetre. If a coloured background or an image runs to the edge, extend it 2 to 3 mm beyond the trimmed size (on every edge). This excess is cut off; it prevents a thin white line. An 85 × 55 mm card is therefore prepared at 91 × 61 mm with 3 mm bleed.
• Safe area: for the same reason, keep text and logos at least 3 mm inside the trim edge.
• Crop marks: guides, added when exporting the PDF, that show where to cut. Ask the printer whether they want them.

CMYK or RGB

• Screens display in RGB (red, green, blue: light).
• Printing uses CMYK (cyan, magenta, yellow, black: the four process inks).
• Some very bright RGB colours (neon greens, electric blues, oranges) do not exist in CMYK: they come out duller. Converting them yourself lets you see the result before printing and adjust.
• Spot colours (Pantone): inks mixed to the exact shade, used in offset and screen printing for a brand colour; only plan for them if the printer offers them.
• Exception: photo and fine art prints are often made from RGB files with an embedded profile; the lab handles the conversion.

Black

• For text, use 100% black only (C0 M0 Y0 K100): sharp, with no colour misregistration on small type.
• For large solid black areas, the printer may recommend a “rich black” (black with a little of the other inks) for a deeper black. Ask them for the mix they recommend: too much total ink dries poorly.

Image resolution

Resolution is measured in dots per inch (dpi) at print size. An image 1200 pixels wide printed at 10 cm has a resolution of 1200 ÷ (100 ÷ 25.4) ≈ 305 dpi.

• 300 dpi: small formats read up close (cards, flyers, booklets, photos).
• 100 to 150 dpi: large format seen from a distance (large posters, banners, roll-ups).
• Enlarging an image in software does not add detail: start from the original file.
• Logos and text must stay vector (not images): they are sharp at any size.

A calculator converts between pixels, dpi and print size.

Fonts

If the printer does not have your font, their software substitutes it and the layout changes. Two solutions:

• embed the fonts in the PDF (the default option in print PDF exports);
• outline them (convert text to paths), mainly required for large format, vinyl and die-cutting. Keep a non-outlined version so you can make corrections.

PDF and PDF/X

PDF/X is a family of ISO standards (ISO 15930) for exchanging print files: embedded fonts, defined colours, declared page size and bleed. The most common are:

• PDF/X-1a: everything in CMYK (and spot colours), no transparency; the “safest” choice for a printer who has not stated their requirements.
• PDF/X-4: allows transparency and colour management (RGB with a profile); recommended by many recent print workflows.

Layout software (InDesign, Affinity Publisher, Scribus…) offers these settings at export. Ask your printer which one they prefer.

What to check, by product

Small formats: business cards, flyers, folded leaflets, postcards, invitations, stationery

• PDF, preferably PDF/X;
• 2 to 3 mm bleed on every edge;
• text and logos at least 3 mm from the trim edge;
• images at 300 dpi at print size;
• colours in CMYK (four-colour process), not RGB;
• fonts embedded or outlined;
• text black as 100% black only.

For a folded leaflet, build the file at the open size and ask for the template: in a roll fold, the panel that folds inside is slightly narrower.

Large format: posters, roll-up banners, banners, window graphics, panels, shop signs

• PDF at 1:1 or 1:10 scale (to be confirmed with the printer: above a certain size, you work at reduced scale and the printer enlarges);
• bleed depending on the finishing: with eyelets or hems, it often reaches 2 to 5 cm;
• images between 100 and 150 dpi at actual size (so at 1:10 scale you need 1000 to 1500 dpi in the file);
• colours in CMYK;
• fonts outlined;
• safe areas for the eyelets and for the base of roll-ups (the bottom of the banner is hidden in the stand).

Self-adhesives: stickers, labels

• vector PDF;
• cut path (the shape) on a separate layer, in a named spot colour (the exact name, for example “CutContour”, is given by the printer);
• 2 mm bleed around the cut line;
• colours in CMYK; on a transparent material, a white underlay on a separate layer, otherwise the colours look see-through;
• fonts outlined.

Publishing: booklets, catalogues, magazines, books, dissertations

• PDF in single pages, in reading order (not as spreads or imposed);
• page count a multiple of 4 for saddle stitching (see Page count);
• 3 mm bleed;
• sufficient inside margins for the binding, especially with perfect binding;
• cover in a separate file, with the spine width calculated according to the paper (see Spine width);
• images at 300 dpi, colours in CMYK;
• fonts embedded.

Plans and A0 prints

• vector PDF to scale;
• page size equal to the print size (A0, A1…);
• line weights of at least 0.1 mm, otherwise fine lines disappear;
• layers flattened, so that the print matches what you see.

Photo prints, fine art, artwork reproduction

• full-resolution JPEG or TIFF file;
• embedded colour profile (sRGB or Adobe RGB, to be confirmed with the lab);
• 300 dpi at print size;
• no excessive sharpening: the lab adjusts sharpness according to the paper.

Textiles: T-shirts, tote bags

• vector artwork or transparent PNG at 300 dpi;
• limited number of colours for screen printing: each colour needs a screen, and therefore a set-up cost;
• dimensions of the print area stated;
• garment colour specified (light artwork on a dark garment often needs an underbase).

Promotional items, mugs

• vector artwork;
• print area and dimensions supplied by the printer;
• colours as spot colours if requested.

Packaging: boxes, folding cartons, bags

• die-cut template supplied by the printer (do not draw it yourself);
• cut and crease lines (the folds) on a separate layer;
• 3 mm bleed;
• colours in CMYK or spot colours;
• fonts outlined.

3D printing

• STL, OBJ or 3MF file;
• closed (“watertight”) mesh: if it has holes, the object cannot be printed;
• units and dimensions checked (a model in inches imported in millimetres becomes tiny);
• minimum wall thickness respected (it depends on the machine and the material).

Rubber stamps

No print file: prepare the text or logo and the desired size; the workshop makes up the stamp.

Before sending: the quick checklist

1. Open the exported PDF (not the source file) and check it at 100%.
2. Check the bleed, the margins and the page count.
3. Make sure no image is blurry at actual size.
4. Proofread the text: a typo printed 500 times is expensive.
5. Ask for a proof (in French BAT, “bon à tirer”) for important jobs: it is the document you approve before printing.

Sources

• imprimeur.paris file checkpoints by product family.
• PDF Association, ISO 15930 (PDF/X): https://pdfa.org/resource/iso-15930-pdfx/
• ISO 15930-4:2003, PDF/X-1a: https://www.iso.org/standard/39938.html

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