While font decisions are dependent on the way the presentation is used, Denny came up with these basic rules for choosing fonts:
Fonts should make presentation pieces easy to read
Presentations that are shared should use common fonts
If a non-standard font is used, it should be embedded
Pick three or four coordinated fonts and don't add any others
The simpler the font, the easier it is to read. Curly Q's and fancy edges are nice for graphics and emphasis, but they become tiring to read after a while. This means more work for the eyes, which in turn limits the amount of information the audience can absorb .
For large amounts of text, use serif fonts. They are easier to read, as the feet help the eye move from one letter to the next .
For headlines and quick text, use sans serif fonts. The lack of feet makes the eye concentrate on the words, increasing the impact of each word.
If the presentation is going to be shared with another user or computer, the presentation fonts should be limited to the fonts delivered with the basic operating systems and the basic Microsoft Office versions. To see the current list of fonts for each operating system and Office versions, check out this PPT FAQ entry: http://www.rdpslides.com/pptfaq/FAQ00256.htm
For fonts that may not be available on other systems, PowerPoint offers the option to embed the fonts into the presentation file. This option is useful, but has some limitations.
First off, the presentation developer must ensure the font is able to be embedded. Many fonts are sold for use on a specific machine only and, therefore, not able to be embedded without breaking copyright rules.
Next, only TrueType fonts are able to be embedded and they will only embed if they are of the right type. To determine if a font is a TrueType font, look at the font dropdown list. TrueType fonts have a TT to the left of their name. If the font name has a printer icon, it is not able to be embedded.
The next criterion is the level of embedding allowed by the font designer. The most restrictive fonts can't be embedded at all. The other three font levels are previewable/printable, editable and installable.
PowerPoint treats editable and installable fonts the same. If they are set up as Type 1 fonts, they can be embedded and used fully on the receiving system. Previewable/printable fonts can be embedded only for viewing and printing. If the text is changed, the font is not used.
Font embedding does have its drawbacks. Beyond needing to know if the font is able to be embedded, the rough size of the font file should be known. Since the actual font file itself is included with the presentation, embedding fonts can greatly increase the file size. If a single presentation has multiple embedded fonts, the file size quickly gets too large to move from system to system in any manner other than via CD-ROM.
One of the best summaries of font embedding information was written by Trina Roberts and can be found in this PPT FAQ entry:
There is a real temptation by all PowerPoint users ( myself included) to use a font because it is there. For example, while testing a presentation you decide a segment needs to be highlighted for some reason.
You start to think: All those fonts on my system and on the internet must have been developed and offered for me to use all together, right?
Next thing you know, you are using a whole new font for the highlighting. This distracts the audience from the flow of the presentation and counteracts design work already done. Using too many fonts in the same presentation leads to seriously ugly slides. Too much variety in the fonts on a slide can distract the participants and make them work too hard to interpret the content.
Use one font for headings and one font for the bulk of the text. Then, select a single font for the emphasis font. Don't have more than three or four fonts on any one slide.
When choosing fonts, be sure they go together in style, formality and size.