Fonts in Fixed Layout ebooks
For fixed layout ebooks, there are no restrictions on the fonts used for text that is on the FLO_BASE layer or used in placed PDFs.
Fonts used on a regular InDesign layers or the FLO_LIVE_TEXT layers must be either OpenType or TrueType. The older PostScript font format is not supported in EPUB or Amazon formats and so cannot be used for live text.
InDesign document fonts and fonts from Adobe Fonts / Typekit are supported for InDesign CC and later.
Fonts in Reflowable ebooks
For reflowable ebooks, fonts from Adobe Fonts / Typekit are supported for InDesign CC and later.
Any document fonts or older PostScript fonts will be substituted.
Although the fonts will be included with the ebook, the reader and reading software will be able to change the font as well as other apsects of the font such as size and colour. This is a feature of reflowable ebooks format.
Font obfuscation is a method to ‘mangle’ or alter the font file so that it is only useful for that particular eBook. As soon as an obfuscated font is taken out of the EPUB, it no longer works.
This is enough to comply the Adobe font licensing requirements.
Can the fonts be embedded in …ebooks?
Font obfuscation is applied by InDesign and supported by CircularFLO.
When creating reflowable Amazon files with CircularFLO, fonts are protected against misuse by the DRM (Digital Rights Management) techniques that Amazon apply.
When using font obfuscation, fonts must be active and available for CircularFLO and so not activated from inside the InDesign document folder.