How to prepare print files

How to prepare files for print

A full checklist of technical requirements: bleeds, colours, fonts, resolution. Save time - and money - by checking the project before sending it to print.

1. Bleed and safe margins

Bleed is a 3 mm margin beyond the cut line on every side of the artwork. It is essential because even the most precise guillotines have some cutting tolerance - without bleed a white edge would appear on the cut.

Common formats and their sizes with bleed:

• Business card 90 × 50 mm → file 96 × 56 mm (3 mm bleed × 4 sides)
• A6 flyer 105 × 148 mm → file 111 × 154 mm
• A5 flyer 148 × 210 mm → file 154 × 216 mm
• A4 poster 210 × 297 mm → file 216 × 303 mm

> Tip: If your project has a background, photo or colour reaching the edge - it must have bleed. If the whole background is white - we still recommend bleed to avoid risk of a thin white line on the cut.

> Warning: keep important elements (logo, text, faces) at least 5 mm from the cut line (8 mm from the edge of the file with bleed). That's the safe margin.

2. Colour - CMYK only (not RGB)

All print files must be in the CMYK colour space (Cyan, Magenta, Yellow, Key/Black). RGB is the space of monitors and cameras - an offset press physically cannot reproduce the RGB gamut.

If you send a file in RGB:

• The colours will be auto-converted - and will almost certainly come out differently than on screen.
• Saturation, bright oranges and fluorescent greens will fade.
• Some greys may pick up a green or pink tint.

> Colour profile: Prepare your artwork in the Coated Fogra 39 profile. If a different profile is used, the file will be automatically converted to Coated Fogra 39, which may shift the colours.

What to avoid: Pantone / spot colours (unless you order a spot-colour print), monitor profiles (sRGB, Adobe RGB) in final files, mixing colour spaces in one project.

3. Convert fonts to curves

All text must be converted to curves (outlines). Without this, if our computer doesn't have your font, the system will substitute another - and the text will look different from your design.

Steps:

• Adobe Illustrator: Select All → Type → Create Outlines.
• InDesign: export with "Convert to Outlines" enabled, or convert text in the layout before export.
• CorelDRAW: Select All → Arrange → Convert To Curves.

> Embedding fonts in PDF: an alternative to "convert to curves" is exporting a PDF with embedded fonts (font embedding). This is safe and preferred for long documents (e.g. books, catalogues) where outlining everything increases file size.

4. Raster resolution - 300 dpi

All raster images (photos, JPG, PNG, TIFF) in the project must have at least 300 dpi at the target print size. Lower resolution → visible pixels, blur, "staircase" edges.

Examples:

• A6 flyer (105 × 148 mm): minimum 1240 × 1748 px
• A5 flyer (148 × 210 mm): minimum 1748 × 2480 px
• A4 poster (210 × 297 mm): minimum 2480 × 3508 px

Important: what counts is dpi at the target size, not in the source file. A 2000 × 3000 px photo has 300 dpi at ~17 × 25 cm. Scaled up to A3 (30 × 42 cm) it has only ~180 dpi - visibly softer.

> Warning: never enlarge raster images "by force". Photoshop cannot create detail that isn't there - it interpolates pixels and blurs the image.

5. File format - PDF/X-1a

We accept files in PDF/X-1a:2001 format. It's the industry standard for print - embedded fonts, flattened layers, colour profiles and no interactive elements (forms, JavaScript).

> Export from Illustrator / InDesign: File → Save As (or Export) → Adobe PDF (Print) → preset PDF/X-1a:2001 → Save. In the "Marks and Bleeds" tab enable Bleeds 3 mm and Trim Marks (if needed).

> Export from CorelDRAW: File → Publish to PDF → Settings → preset PDF/X-1a. In the "Color" tab set "Output all objects as: CMYK".

We also accept: TIFF (one file = one page, CMYK, 300 dpi, no layers, LZW compression). High-quality JPG (CMYK, 300 dpi) - only for simple projects without text.

We do not accept: PSD, AI, INDD, CDR (source files), DOC, DOCX, PPT, PNG with transparency.

6. Overprint and black overprint

Black text and small elements should be set as C0 M0 Y0 K100 (pure K100 black). This gives sharp, legible letters without risk of colour misregistration.

> Rich black: for large black areas (solids, backgrounds, thick frames) use rich black: C40 M30 Y30 K100. Pure K100 over a large surface looks "washed out", dirty grey.

Overprint is an option where one element prints on top of another instead of knocking it out. Default behaviour:

• Black K100 → prints overprint (on top)
• Other colours → print knockout (cut out the background)

An unintended overprint on a coloured element makes it "mix" visually with the background - e.g. yellow overprint on blue will come out green.

7. Total ink coverage (TIC)

Total ink coverage is the sum of all inks (C + M + Y + K) at the darkest point of your design. The more ink lands in one spot, the harder it is to dry and to stay on the paper.

Safe maximums:

• Coated paper (glossy or matte): up to about 300%.
• Uncoated, offset or ECO paper: up to about 260-280% - these papers absorb ink more slowly.

> Too much ink = trouble: when the ink sum exceeds the safe threshold, the print smudges and rubs off, takes longer to dry (sheets can stick together) and the ink may crack and flake on folds. This usually happens with dark backgrounds built from an over-full CMYK mix.

> Safe deep black: our recommended rich black C40 M30 Y30 K100 adds up to ~200% - deep, clean and perfectly safe. Don't build black from values like C100 M100 Y100 K100 (400%) - that's a fast track to smudging.

8. Minimum text size and line weight

Very small text and thin lines are easily lost in print - especially in any colour other than pure black, where several inks have to line up at once. These minimums protect legibility:

• Body text: 7-8 pt minimum.
• Contact details, footers, fine print: 6 pt minimum.
• Reversed-out text (light on dark): add 1-1.5 pt - a reverse "tightens" the letters, so use e.g. 8-8.5 pt instead of 7 pt.
• Black line on a light background: 0.1 mm minimum (thinner may disappear).
• White line on a dark background (reverse): 0.2 mm minimum - a thin white line gets swallowed by the dark.

> Avoid thin weights at small sizes: Light and Thin font weights have very fine strokes. At small sizes they can break up or vanish - for fine print, prefer Regular or Medium.

9. Saturation, gradients and effects

What looks great on screen can be capricious in print - a few small habits keep the result on target.

• Very low saturations (1-5%) often disappear in print - a pale fill may not show up at all, or come out patchy. If a colour should be visible, give it at least a dozen percent or so.
• Gradients can show visible banding (steps). A subtle noise applied over the transition helps - it breaks the even steps into fine grain.
• Greys are best built from full CMYK rather than black alone - that gives a deeper, warmer tone instead of a flat, "dirty" grey.
• Effects (shadows, transparencies, blurs, complex gradients) are best flattened to a CMYK 300 dpi bitmap before you hand over the file. That way they print exactly as you see them - no surprises during processing.

> Why flatten effects: live transparencies and effects can be interpreted differently at the prepress stage. Turning them into a plain CMYK 300 dpi image is the surest way to get what you see onto the paper.

10. Printing on CDs/DVDs

Disc printing has a few rules of its own - good to know before you build the design.

• Supply the artwork as a 12 × 12 cm square - don't cut out the circle shape. We cut the round print area (and the centre hole) ourselves; you provide a full square with the graphic extending past the disc area.
• Colour profile for discs: Coated Fogra 27 (different from paper - the disc surface takes ink differently).
• Colour: CMYK, resolution: 300 dpi.

> Which profile when: remember the difference - CDs/DVDs use Coated Fogra 27, while all other paper products use Coated Fogra 39. Discs are the only product where we switch the profile.

11. The golden rule of the file

Finally, the simplest rule and the one most often forgotten: leave only what is meant to be printed in the finished file.

> Remove anything that isn't the artwork: no guide lines, positioning frames, colour scales, notes, test text or extra markings. Anything left in the file besides the artwork itself may get printed by mistake.

The only exception is standard print marks (bleed and registration marks) generated by the PDF export - those are needed and we know how to read them.

12. Multi-page print (brochures, books)

Send brochure / book / catalogue pages one by one, in reading order (1, 2, 3, ...) - not as "spreads".

> Page count: must be a multiple of 4 (for saddle-stitched brochures) or a multiple of 2 (for perfect-bound brochures). Blank pages count too - if you don't have content on the last page, add a blank.

Inner margins (binding):

• Saddle-stitched brochure: 5 mm from the spine.
• Perfect-bound brochure (32+ pages): 10 mm from the spine - the glue "eats" ~3-5 mm of the visible area.

13. Cutting to shape - packaging and contour-cut stickers

This section applies only to jobs where the shape is not a plain rectangle: boxes and packaging folded from a flat net, contour-cut stickers, labels with an unusual outline. If you are ordering a leaflet, a business card or a poster, none of this section concerns you - the points above are enough.

The contour is cut by a flatbed plotter straight from the file, with no tooling to make, which is why short runs are viable. On larger runs the same shape is produced with a cutting die, a tool made for that specific design. The file is prepared the same way in both cases, so a net made once will also serve when you move to larger production.

> Cut and crease lines must be vector. The plotter follows a path, not a picture. An outline drawn in photo-editing software is invisible to the machine, however perfect it looks. The lines have to be vector curves.

• Cut line - red, hairline weight. A closed contour of the finished element plus any openings, for example a window or a slot for a hanger.
• Crease line (fold position) - cyan, hairline weight. It is a groove pressed into the board along which the material folds; it does not go through.
• Both lines in one document, on two separate layers. Cutting and creasing always travel together.
• A separate print file - artwork only, with no cut or crease lines. Left in the print file they would come out as visible strokes on the finished pack.

Two arrangements are acceptable, pick whichever suits you - we treat them the same:

1. Option A: one PDF, two pages. Page 1 - the artwork for print. Page 2 - the cut and crease lines only. Both pages at the same size.
2. Option B: two separate files. One with the artwork for print, one with nothing but the cut and crease lines. Name them plainly so there is no doubt which is which.

> Scale 1:1, nothing to resize. The artwork and the lines must share the same page size and the same origin point, at 1:1 scale. No file may need enlarging or reducing - rescaling shifts the print against the contour and the offset shows once the job is cut.

If you do not have a box net ready, you do not have to draw it yourself. Give us the dimensions of the product that goes inside and how the box should open - we will choose a construction and hand you a net with the lines marked.

14. Pre-flight checklist

Tick all points before uploading the file - it saves a day of waiting for DTP feedback:

• [ ] 3 mm bleed on every side
• [ ] CMYK colour space, embedded ICC profile
• [ ] Fonts converted to curves or embedded
• [ ] Raster images 300 dpi at target size
• [ ] PDF/X-1a:2001 format
• [ ] Black text as C0 M0 Y0 K100, rich black as C40 M30 Y30 K100
• [ ] Total ink coverage up to ~300% coated, 260-280% uncoated/ECO
• [ ] Minimum sizes: text from 6-8 pt, lines from 0.1 mm (white reverse from 0.2 mm)
• [ ] Effects and transparencies flattened to a CMYK 300 dpi bitmap
• [ ] Only for cutting to shape (boxes, contour-cut stickers): vector lines, cut and crease in one document, print file separate, everything at 1:1
• [ ] Golden rule: only what should print left in the file (no guides, frames, colour scales)
• [ ] Pages one by one, in reading order (multi-page jobs)
• [ ] No layers, no transparency in the final file