When you order custom posters, business cards or other custom products, you will be asked to upload a PDF file containing your layout. To make sure that your PDF can be printed properly, it must meet certain quality criteria. If a PDF file looks good on screen and prints nicely on your home printer, that is no guarantee that it will also print properly on a printing press.
There are international standards that specify how a PDF file can meet the requirements for professional printing. Our guidelines are inspired by such a standard: the GWG_SheetSpotHires_1v4 specifications for general offset and digital printing. By meeting these guidelines, you are sure your document can be printed properly, and because we need to spend less time altering or correcting the file, it will move faster through our shop.
- Your PDF files must contain all the pages that need to be printed. These pages must be in the correct order. The document size should be the same as the trim size of the final piece.
- All the pages within the PDF document must have the same size.
- There should be no empty pages. Pages may not contain annotations (sticky notes) in the area that will be printed.
- If the design calls for images or color bleeds, there should be a minimum of 3 mm or one-eighth of an inch on all sides of that trim.
- The recommended PDF file format is PDF/X. We accept either PDF/X-1a or PDF/X-4 files. Professional page layout applications such as Adobe InDesign can export layouts using this file format.
- A PDF/X file contains a so-called output intent, which is a way of defining what the expected color space is for printing the file. Our recommended output intent is described in a color profile that is called ISO Coated v2 300% (ECI). It can be downloaded from the ECI web site.
- 1-bit images, sometimes referred to as line-art, should have a resolution of at least 550 ppi. Ideally the resolution is 800 ppi or higher.
- Grayscale and color images should have a resolution of at least 150 ppi. Ideally the resolution is 225 ppi or higher.
- The above guidelines do not apply to small images that are less than 64 pixels wide or high, such as icons.
- All fonts should be embedded in the PDF file.
- The ‘Courier’ font should not be used in the PDF, since this font is often used as the default substitution font if the application that generates the PDF document does not have access to all fonts. It is no problem to use other Courier variations, such as ‘Courier New’.
- All 100% black text that is smaller than 10 points should be set to overprint.
- White text should not be set to overprint, since this would make the text invisible on the printed page.
- Text cannot be smaller than 5 points. If text is colored, it should not be smaller than 8 points since it is very difficult to print such text with all the colors aligned properly.
- If text contains at least 85% black and also contains cyan, magenta and yellow, the total ink coverage should not exceed 280%.
- White lines or paths should not be set to overprint to avoid them not being visible on the printed page.
- Black lines with a thickness of less than 2 points thick should be set to overprint.
- Colored lines should have a thickness of at least 0.25 points. If they are colored with just one process color, they should be at least 0.124 points thick.
- The total ink area coverage should not exceed 320% for any square surface that is larger than 15 mm.
Application specific guidelines
Adobe InDesign CS2 to CS6 & CC
To properly export PDF files from Adobe InDesign we recommend to install the GWG preset which can be downloaded here.
Please do not create documents in Adobe Photoshop. Unless you are very careful, text is stored as an image in a Photoshop document. This causes it to be printed slightly blurred. Editing images in Photoshop for inclusion in a layout is obviously no problem!
QuarkXpress 7.2 to 9.3
Settings and documentation on how to use them can be downloaded here.