These are the TOP 10 problems when using PDF in graphic arts. Don’t take my word for it, this list actually comes from Adobe.
- The resolution of images is too low.
- Fonts are not embedded in the PDF.
- The wrong color space is used.
- The information about trim or bleed are incorrect.
- There is an inconsistency with the native file. The original page, as viewed in QuarkXPress or InDesign or whatever other application looks different from the PDF. Hairlines might be different or gradients have changed.
- A spot color is misnamed or it is accidentally converted to a process color.
- Images are compressed too much. This causes a quality loss and in some cases artifacts appear inside or around the images.
- The page size is incorrect.
- There are problems with transparent objects.
- ICC profiles are missing or incorrect.
One of the reasons why many of these problems go undetected is that designers have the habit of making proofs from their lay-out, checking those proofs and then creating PDF files. These PDF files don’t get looked at, they are sent straight to the agency or printer. It would be far better if designers created PDF files and then made a proof of these files. This way the consistency between supplied file and proof is much better!
Next to PDF files having some kind of issue, it can of course happen that a PDF cannot be ripped or rendered at all. Here are some typical things to try when this happens:
- Use PitStop or another tool to get rid of any irrelevant data in the PDF file. Delete OPI comments, forms, scripts, animations,… and then use ‘Save As’ to create a new clean PDF file.
- Refry the PDF file if you don’t have access to the source file(s).
- If you have the source files, try recreating the PDF using a different procedure: if the problem file was creating by exporting to PDF, try creating a PostScript file and distilling that. If the problem file was created using Distiller or Normalizer, try using ‘Export to PDF’.
- If you have access to the source file: clean it up and recreate the PDF: Make sure that any spot colors that are not printed as spots are converted to CMYK in the original file. Delete any unused data (stuff on the paste board, elements hidden underneath others, unused pages,… )You also may want to merge layers, paths or channels. Then do a ‘Save As’ to create a clean source file.
- If everything else fails, try opening the PDF in Photoshop and saving it as an image. This operation converts all text to bitmap so it really has a huge impact on the quality of the output but if everything else fails, this is your last resort.