If the fonts you use in your PDF document are not installed on the user's computer your document may not be displayed correctly, because substitute fonts will be used. You can solve this problem by embedding the fonts in your PDF document, but this can increase the size of your document considerably, particularly if you are using Unicode-based languages like Asian languages.
If you need to keep your PDF files as small as possible it is advisable to only use standard fonts like Arial and Times Roman that will be installed on all users' computers. You can then reduce the PDF file size by adding these fonts to the exclusion list and by embedding only font subsets of the characters used in your project (see below). This is often not possible for languages with special character sets, particularly Asian languages.
If your fonts are rendered with strange spacing and seemingly incorrect characters the problem is generally the reference printer driver used for generating PDFs. See here for information.
In general you should always embed fonts for languages with special character sets, like Russian, Greek and Asian languages in particular. If you experience problems with the normal embedding modes, try the option for Type 3 fonts, even if you are not using Type 3 fonts in your project. Help+Manual will then embed the fonts in Type 3 mode, and this often solves problems, particularly in documents where Asian languages are mixed with text using the English alphabet.
It is generally best not to use CID font embedding for these languages. See CID font embedding in the PDF chapter for more details.
If you must embed fonts you can reduce the size of your PDF files by selecting the right embedding option.
Embed TrueType fonts embeds all TrueType fonts except the fonts you add to the exclusion list (see below).
Embed symbol fonts only embeds fonts like Symbol and Wingdings. This ensures that special characters that depend on these fonts will be displayed correctly. Other fonts not found on the user's computers will be substituted with available similar fonts.
Use Base 14 Type1 fonts tells Acrobat to substitute its own built-in fonts. This switches off font embedding and will work adequately if your fonts are similar enough to the Base 14 fonts (Times/Mac or Times New Roman PS MT /Win; Helvetica/Mac or Arial MT/Win; Courier, Symbol, and Zapf Dingbats, each with regular, bold, italic or oblique, and bold italic styles).
Embed TrueType subset only embeds the code pages of the TrueType fonts that are actually used in your project.
Embed TrueType subset (used characters only) saves even more space by only embedding the characters that are actually used in your project. Note that this can slow down publishing considerably with larger projects.
Embed Type 3 Fonts is fur using Adobe Type 3 fonts instead of TrueType.
Embed CID Fonts generates virtual fonts in the PDF that are encoded with CIDs (Character IDs). In some documents this can provide better rendering. However, this option may not be optimal for special character sets like Russian, Greek and Asian languages. With these fonts, you will often find that CID fonts look good but the PDF file is very large and the text cannot be selected or searched. See CID font embedding in the PDF chapter for more details.
Do not embed these fonts:
If you choose Embed TrueType fonts you can reduce the size of your output file by excluding all the common fonts that all users are likely to have installed on their computers.
All the fonts you add to this list will not be embedded in your output file.
Some Windows TrueType fonts like MSGothic are implemented as "collections" of font variants with the extension .ttc instead of as the standard TrueType .ttf font package. Font collections can't be embedded directly in PDF, but if you leave this option on Help+Manual will automatically convert them to Type3 and embed them. Then they will work fine.
We recommend leaving this option on. It won't cause any problems with normal fonts and it will eliminate "cannot embed font" errors with TrueType font collections and other problem fonts.
Optimize embedded fonts for cross-platform:
This option can improve the rendering of fonts in different PDF readers on multiple platforms.
Export as glyphs
PDF frequently has problems with symbol characters and bullet characters used in lists. To deal with this, Help+Manual can export these characters as glyphs (small vector graphics). These are then always "correct" because the display of a glyph is never affected by the way a font is rendered. If you ever have problems with this, for example when trying to convert your PDF in an external program, you can turn this option off here. Then the symbol characters will be exported as normal text characters, which may be rendered incorrectly in some configurations.
Special symbol fonts
Not all symbol fonts are recognized automatically. You can add symbol fonts here so that they will be referenced directly. Help+Manual automatically recognizes FontAwesome, Fontello and Webdings, for example, but you can add additional symbol fonts as well.
About CID font embedding:
The Embed CID Fonts option in Configuration > Publishing Options > Adobe PDF > Font Embedding is a rather esoteric technology that can reduce the size of your PDF and improve font rendering.
When you activate Embed CID Fonts the characters actually used in the project are embedded in the PDF file as "virtual" fonts, using a special internal format and CID (Character ID) encoding of the characters.
This only works with fonts that actually contain all the characters you need to display. If you select a normal western font like Trebuchet that does not contain the characters for the language you are using you will have problems. The text will automatically be rendered as graphical glyphs because the characters are not available, which will make your PDF files huge. Also, it will not be possible to select or copy text from the PDF, because it does not contain text, only graphics.
Effectively, this means that Embed CID Fonts only works with Unicode fonts that contain the full Unicode character set!
See CID font embedding in the PDF chapter for more details.