ABCs of print files

When preparing print files, keep the following in mind:

Bleed

If background colors or images run to the paper’s edge, you must add 3-5 mm of bleed. (The exact amount of bleed depends on the printing process used, so check with your sales manager).

Colors

For normal four-color printing, make sure that all colors in the file are defined in CMYK color space. Text is usually set to black (K). Unless you are purposefully adding an additional Pantone spot color, ensure that no colors are defined as spot, as they will convert to CMYK and render differently than expected.

Image quality (resolution)

The resolution of images should be between 200–300 dpi. It should also be 2 x lpi. For example, if lpi is 150 (for a magazine), dpi should be 300; if lpi is 85 (for a newspaper), dpi should be 170. Note that increasing resolution artificially may not produce the desired result. Use your photo-editing program to check the inherent resolution of images.

PDF profiles 

When preparing a print file in a layout program, use the PDF/X:1-a (2001 or 2003) standard profile. When exporting the file to PDF, use the ICC profile that corresponds to the paper and printing process used. When generating a PDF file, ensure that all fonts are embedded.

Overprint

Incorrect or unintended use of overprint can significantly change the final result, so be extra careful. If applied to fields of color, it can produce undesired shades. For instance a blue object set to overprint on a pink background will produce a purple shade. Overprint can be used for pure black (CMYK 0.0.0.100).

Verify overprint settings in your layout program or in AcrobatPro (by selecting Simulate Overprint in the Output Preview menu).

Rich black on a very large surface 

A large surface covered in black (CMYK 0.0.0.100) may appear dull, depending on the chosen paper. To achieve a rich black surface, set black to print through four colors (Rich Black, CMYK 35.60.60.100). Rich black is meant to be used only on large surfaces. For thin lines or small text sizes, it’s best to stick with clear black (CMYK 0.0.0.100).

Empty page

Any blank pages in your publication must be included in the print file.

Thin lines on color surfaces

Be aware that in four-color printing, thin lines and small type may appear blurred when placed on colored surfaces or color photos.

Indicia

We will add all required printing indicia to the PDF file. There is no need to add color bars, registration marks and other printing indicia to your file.