Each design theme has a font family defined for headings and for body text. The same font family extends to text entered into text boxes and on shapes and SmartArt. The simplest way to control font family throughout a presentation—which is a good idea, because it gives a consistent, professional look to the presentation—is to stick with the default font choices already built-in to the font themes used in PowerPoint 2013. This is a rule more honored in the breach than the observance, unfortunately, because people just seem to have a thing about unusual font choices, but if good advice can prevail, I urge you to put aside your love of cursive or decorative fonts, and stick with the basics.
Text in Placeholders
Font family and size entered in text placeholders (titles and bulleted items) get their font family, font size and color from the design theme you select. They can be changed independently from the other theme elements (colors, effects, and background art). To do so, click on the View tab, select Slide Master View, and click the drop-down on the Fonts group, to reveal the theme fonts gallery. Each font theme set contains a font family for Header text (i.e., slide titles) and one for Body text. In the font themes at the top of the drop-down these are the same font, just in different font sizes. In those towards the bottom of the themes these are different font families for headers and body text, Like Times New Roman for headers and Arial for body (see the illustration below).
Note that you can also create your own, custom font theme by clicking the Customize fonts… command. (The font theme can also be changed from Normal View using the Font gallery drop-down in the Variants group on the Design tab).
A lot of nonsense has been spouted about font selection for slide presentations and their effect on audiences. To me the only important factors are legibility, and ease of use when re-purposing fonts on existing slides. Therefore, my advice is to stick with the basics. Use one of the font sets towards the top of the font theme drop-down, where the header and body fonts are the same, and stick with it. Unless you have a compelling reason, go with the font theme associated with the design theme itself. Avoid the impulse to use a “cool” looking font. With respect to serifed vs. sans serif fonts, I think it is a matter of taste. I personally favor the clean sans serif fonts, but others will feel differently. As long as fonts are legible to those in the back of the venue at which you will be presenting, they serve their purpose. Above all, avoid decorative, fantasy, and cursive fonts.
Font color needs to provide high contrast with the slide background, so it is wise not to modify the default theme colors with respect to header and body fonts, but to make your text even more legible I recommend, where possible, to increase font
To increase font sizes for text in placeholders on all slides in your presentation, increase them on the Slide Master. In the sample presentation we are building in our workshop, for example, right-click in the title area of the slide master (the header text), and increase its size to 54 point. Don’t worry that the default “Click to” text in the placeholder wraps outside the placeholder. We will never create a slide title long enough to wrap. Brief, to-the-point titles are what to strive for; not wordy titles. By increasing the font size of the default slide title we have increased its legibility.
Also increase the font sizes of all of the bulleted items (body text). In the presentation we are creating we will not use bulleted items, but many presentations do. Displaying bulleted items to third, fourth and fifth levels should not actually happen, but in case it does, increase their font sizes. As with titles, avoid wordy bulleted items. In the instance, I recommend bulleted item sizes of 40pt for level one, 36pt for level 2, and so on, down the scale. Larger font sizes = increased legibility. Do not create bulleted items that duplicate what you are going to say. Use brief, pithy bulleted items that summarize your points. They call it a “point” for a reason. Any elaboration should be done by orally you, the speaker. That way your audience will not be reading ahead, or be distracted by reading your wordy slide while you are speaking. In my opinion the font sizes of the bulleted items on the default PowerPoint themes are all too small, and ought to be increased. If you want to create a presentation with a lot of words, it probably should be a Word document, and not a PowerPoint presentation, and should be delivered as a download rather than in-person.
As I say, it is better from the start to pick a font that provides high contrast, increase its size to increase legibility, and stick with your choices.
Text Box Text
Text in text boxes is different from text in placeholders. There is no simple way to adjust its font size for all text boxes in a presentation. I wish there were—actually, I wish what Microsoft would provide is a set of styles, as in Word, to apply to various text boxes, any of which could be modified as desired, but they do not. I think the theory is that text boxes can contain anything, from large blocks of text to tiny, single word labels or grouped labels and graphics. Whatever the theory, to change the font size in a text box you need to do it in the actual text box in the presentation itself, and not in slide master view.
If you are just beginning to create your presentation, however, and want to establish a text box style for all text boxes, you can adjust the default font size from the get go. This will not affect text boxes you have already creating, but will become the default text box style. Here’s how.
First, select the text in the text box you want to change, and modify it as desired. In the case of our sample presentation, I want to use a much larger font size than the default 18pt font used by my theme (Ion). Drag the cursor over the text in the text box, right-click the selection, and from the mini toolbar change its size. In the case of our sample presentation, I want my text box text to be 54pt. Once again, I want it legible from the back of a large room, and I do not plan to create text boxes that are too prolix.
Now, click the border of the text box (the dashed line around it) so that it becomes a solid line. With your cursor over this solid line (so that it is a 4-headed arrow) right-click, and from the context menu choose “Set as Default Text Box.” The font size (and other font attributes) of this box will be the default for all subsequent text boxes you create in your presentation.
The same procedure works for text size on a drawn shape. Once set, it can become the default shape.
The nomenclature is somewhat confusing, because what you are really doing is setting the default font style on the shape, and not setting a default shape at all. After setting a default shape in this manner, you can draw any shape, and when you type text on the shape it will have the attributes (font family, color, size) as that set on the “default shape.”
The following video summarizes the techniques presented here.