Adobe Illustrator & PDF

This page discusses PDF support in Adobe Illustrator

  • Using Illustrator as a PDF editor
  • IsPDF the internal file format of Illustrator?
  • Illustrator CS3 notes

Illustrator as a PDF editor

Adobe never positioned Illustrator as a PDF editing tool but the application is capable of opening many (but not all) PDF files for editing. Just be aware that you may have serious issues with:

  • Fonts – Illustrator cannot properly use fonts embedded in a PDF files when those fonts haven’t been installed as system fonts as well. This can cause font substitution issues. If you replace a missing font by a similar one, characters may disappear or get replaced by others. Illustrator also cannot deal with subsetted fonts with custom encodings. One way of avoiding issues with fonts is to outline all fonts in the PDF, prior to opening the file in Illustrator. Unfortunately thin and small fonts ‘fatten up’ a little when they are outlined.
  • Transparencies – Illustrator doesn’t support all the transparency features of PDF.
  • Color – When you create a new document in Illustrator, it is either an RGB or CMYK document. PDF files can contain a mix of RGB and CMYK data
  • PDF stuff – Some of the nice PDF features such as bookmarks or hyperlinks get lost when a PDF is opened in Illustrator. This isn’t much of an issue if the PDF is meant to be printed only. If it is also distributed electronically, this can be a showstopper.

As a general rule, it is better to use Acrobat and plug-ins like PitStop or other PDF editing applications to make last-minute changes to PDF files.

PDF as Illustrator’s native file format?

Illustrator doesn’t really use PDF as its internal file format.

  • Illustrator’s native file format is .AI. By default, Illustrator embed a PDF in .AI files. You can disable this by deactivating the ‘Create PDF Compatible File’ option in the settings when saving a file. This leads to a smaller file size but the disadvantage is that other applications may not be able to import the .AI file properly. When you import a .AI file in an InDesign document, InDesign actually imports and processes the embedded PDF.
  • Illustrator can also save documents as PDF files. When it does so, it also embeds its own data within the PDF. This way you can open a PDF generated by Illustrator in the same application and still retain all editing capabilities.

You can find a more elaborate explanation in Mordy Golding’s blog.

Illustrator CS3 notes

A lot of people seem to struggle with bleed/crop marks/pdf boxes when using Illustrator 11. You can read an excellent explanation of CS3’s bleed handling on this page.

2 thoughts on “Adobe Illustrator & PDF

  1. We have an issue when saving an illustrator file as a PDF. Characters within the AI file turn bold and appears to increase size when saved as a PDF. Is this a normal file conversion problem? How can it be fixed to not happed? Any help would be great.



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