Setting up print-ready files: bleed, colour, resolution

Checklist

Format: Set up the exact final size.
Bleed: Backgrounds and images that run to the edge extend about 3 millimetres beyond the final size.
Safety margin: Keep important content at least 3 to 5 millimetres from the edge.
Colour space: CMYK for print, not RGB.
Resolution: About 300 dpi at final size.
Fonts: Embed them or convert them to outlines.
Black: Text in pure black, no “rich black” in small type.
File format: Print PDF with bleed, unless the printer specifies otherwise.

Common mistakes

Missing bleed leads to white edges.
Images with too low a resolution look blurred.
RGB colours change in print.
Text too close to the edge gets cut off.

Worked example: DL flyer

Suppose a flyer with a final size of 99 × 210 millimetres is to have a coloured background running to the edge. The file is therefore set up with 3 millimetres of bleed on every side, which makes 105 × 216 millimetres. Text and logo stay at least 4 millimetres from the final size, so within the safety area. A photo that is to be printed 10 centimetres wide needs around 1,181 pixels in width at 300 dpi (10 cm divided by 2.54, times 300). If it has only 600 pixels, it is not enough for that size, even if it looks sharp on screen. Finally, you export a PDF with bleed, embedded fonts and, depending on the printer’s specification, a particular colour profile.

Myth versus fact

Myth: As long as the image looks good on screen, it is fine. Fact: Screens usually show fewer pixels per inch than print needs, and they can display colours that CMYK cannot reach, such as very bright blues and greens. These look duller in print. If you know this beforehand, you can plan for it.

Decision aid: resolution by format

Business card, flyer, brochure: about 300 dpi at final size.
Posters, banners and other large formats: if they are viewed from a greater distance, much lower dpi is often enough. Clarify this with the printer, see Large format.
Logos and line graphics: preferably as vectors (PDF, SVG, EPS), because they stay sharp at any size.

Further mistakes that are often noticed

Forgotten fold: For folded products the fold has to be taken into account in the layout, otherwise text runs into the crease.
Lines too thin: Hairlines below about 0.25 point can disappear in print.
Overprint set wrongly: White text set to “overprint” is invisible in print.
Colours set up as spot colours when not intended: This can create extra printing plates and costs.
Multi-page documents in the wrong order: Ask whether the printer expects single pages or printed sheets.

Requirements vary with the printing process and the paper, so the printer’s data sheet is worth checking as a cross-check. These rules also apply to a business card.

Checks before sending

In your PDF software, check the page size: does the format include bleed?
Check fonts and image resolution in the document properties.
View the PDF in the output preview and check that the colours are CMYK and not RGB.
Page through all the pages: order, margins, cut-off text.
Make a test print at 1:1 scale if only a single print run is possible.

When a file check by the printer is worthwhile

Many printers check submitted PDF files automatically and report missing bleed, too low a resolution or wrong colour spaces before the job goes into production. For runs of a few hundred copies or more, or for jobs with a tight deadline, this check is worthwhile, because a mistake costs not only material but also time. When you place the order, ask explicitly which check is included and what later corrections cost.

Ask the printer for their data sheet. We prepare files so that they are print-ready, see Printed matter.