The <PubML>™™ Publishing Tools come with a selection of default type styles and fonts. Use the Fonts tab to add typefaces, or use the default selections.
Probably, the default typefaces will work well in most cases. Leave this section alone unless you have specific typographical needs.
The pre-installed fonts have been carefully selected to work with eBook typography. They should meet most of your needs, but if you wish to modify them, keep a few important things in mind:
So when adding web fonts, it’s important to also select a “fallback” font—a typeface selected from a list of standard fonts installed on every computer that can be substituted if the desired web font is not available.
In the case of a Google Web Font like Crimson Text, Georgia is selected as a fallback. In other words, if your eBook is offline and unable to access Crimson text from Google’s font servers, it will display the text in the Georgia typeface.
Font Selection:
Read up on book typography before adding new typefaces. You may wish to select an unusual font for titles, but very few fonts are actually suitable for body text—including old standards like Times New Roman. Be sure your selected typeface comes in multiple weights and styles (bold, italic, etc.).
Your Font Library
The Fonts tab contains all of the fonts for all of your eBooks. Adding fonts does not add file size to your books. Fonts added here are available to the entire <PubML>™™ publishing system and not only to a particular book.

The Font List
A list of installed fonts is available at the bottom of the Fonts panel. Use this list to modify or preview a font. Type in the field below the font name (where you see the alphabet) to preview specific words or phrases in a given font. Pre-installed fonts are used by default text styles and can not be edited deleted.Unlike many conventional eBooks, <PubML>™ web books allow you to use embedded web fonts for better typography. Several default fonts are already included due to their suitabilty for book typography but you can add your own if you wish.
Adding fonts is a top-level function (the "Fonts" tab is in the top row). Fonts you add to your copy of the <PubML>™ Publishing System are available for inclusion in every eBook but won't necessarily be exported with every eBook. In English, this means you can load (for example) six different web fonts and then use two of them in one book and four of them in another. Each individual book will be exported with only the fonts that it actually uses.
You'll include specific fonts from your font library later when you create styles for an individual book.