Choosing Fonts for Slides That Read From the Back of the Room

A slide is read under the worst conditions any text faces: from across a room, on a screen or projector that has lost half its contrast to the lights, by people who are also listening to someone talk. Type that looks refined on a laptop can be unreadable there. The good news is that the fixes are simple and mostly about weight and size.

What survives a projector

• Regular weight or heavier. Light and thin weights lose their strokes to glare and to the soft focus of a projector. Something that looks elegant on your screen will look faint on the wall.
• A large lowercase. Faces with big x-heights read bigger at the same point size, which buys you distance.
• Low contrast between thick and thin. High-contrast serifs are beautiful up close and lose their hairlines at a distance. Save them for the title slide, large.

How big is big enough

The old rule of thumb — no text on a slide smaller than 30 points — is a good one precisely because it is uncomfortable. It forces fewer words per slide, which is what makes a presentation readable in the first place. In practice: titles around 36 to 44 points, body text 24 to 32, and nothing under 18 except a source credit. If the text does not fit at those sizes, the slide has too much on it.

Families that work well on slides

Merriweather Sans was drawn to stay open and sturdy on poor screens, which is exactly what a projector is. Inter and Ubuntu Sans are neutral and clear at every size. Mona Sans has a width axis that lets a long title go narrower without switching families. For a title slide with more character, DM Serif Display is striking at size, paired with any of the sans above for the rest.

Stopping your font from being swapped

The most common presentation disaster is not a bad font choice; it is a good font replaced by a default one because the computer running the slides does not have it installed. Each program deals with this differently.

• PowerPoint can embed fonts in the file — look for the embed option in its Save settings. Embed all characters if anyone else will edit the deck.
• Keynote does not embed fonts. If you present from another machine, export a PDF or make sure the font is installed there.
• Google Slides only offers the fonts in its own menu, and you cannot upload your own. Many of the families here are in that menu already, because they come from the same open library.

The full explanation of that last point is in what a variable font is, and installing a font in Word and PowerPoint walks through the installation itself.