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

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](https://imprimeur.paris/en/guides/calculateurs/) 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](https://imprimeur.paris/en/guides/pagination-brochure/));
- 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](https://imprimeur.paris/en/guides/epaisseur-dos/));
- 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

## Frequently asked questions

### What is bleed?

A 2 to 3 mm margin added around the trimmed size by extending the background. It prevents a thin white edge if the cut is slightly off.

### My file is in RGB. Is that a problem?

The colours will be converted to CMYK at printing and some very bright ones will look duller. Convert them yourself to control the result, except for photo prints.

### What resolution for a printed image?

300 dpi at print size for small formats; 100 to 150 dpi is enough for a poster or a banner seen from a distance.

### Which file format should I send?

A PDF, preferably PDF/X (PDF/X-1a or PDF/X-4), with fonts embedded. Photo prints are usually made from JPEG or TIFF.

### Why should black text be 100% black only?

A black made of all four inks is hard to keep in register on small type and gives blurry text. Black alone (C0 M0 Y0 K100) stays sharp.

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Updated on 1 November 2026. Source : https://imprimeur.paris/en/guides/preparer-son-fichier/