Your choice of font can make the difference between clear, professional-looking slides and unreadable, amateurish slides. It’s that important. Everyone knows you shouldn’t use something like Curlz, and most people are now aware of the cheapening effect Comic Sans has on any text. But there are more subtle font features you should consider, some of which may affect the audience’s impression of your presentation at a subconscious level. 

Two things are critical: the style of the font and the size of the font. When making slides, many people scroll through the list of fonts and pick one that looks pretty, attention-getting, or unique. Then they adjust the size of the font so that all the text they want to put on a slide will fit. Let’s take a look at how to do this in a more thoughtful way.

Font style

Pretty or unique fonts can undermine the credibility of your presentation and make words illegible. Basic, clean, almost-boring fonts will allow your words to shine through.

What not to do

Here are some examples of fonts that will make a medical presentation seem less authoritative and professional:

These fonts make medical text look cute, fussy, strained, or insubstantial. They might work great in a different context (I like Modern No. 20 a lot), just not here.

Same thing goes for fonts that are complicated. Even fonts that seem to look professional may have too much going on or have letters that are spaced too closely together. Here are some examples of fonts that give a crowded, less-than-legible look to your text:

Notice that most of these fonts have serifs (those little extra lines at the top and bottom of letters). Generally, serif fonts are good for reading text in a book or other document. For medical presentations, though, most of the best fonts are sans serif.

Finally, just on principle, don’t use Times New Roman or Arial. Times New Roman is way overused, to the point where it looks boring. And Arial – well, I just hate Arial. It makes me a little sick inside.

How to do it right

So what font style should you choose? Find one that is simple in its design and shows up clearly on the big screen. Sans serif fonts are best. The design should not draw attention to itself at all but should be almost invisible – it should allow your words to be the main attraction.

Some good fonts for medical presentations include:

Yeah, I know. It’s a much shorter list. Bad fonts outnumber good ones by, oh, 100 to 1. If you really must use a serif font, Calisto works fairly well. Garamond does not; it has a rather wimpy look.

Font size

A common mistake is to adjust the size of the font to the text on your slide. This can lead to very small fonts that are not readable from the back (or even the front) of the room. In general, your font should be at least 28 pt (or at the very least, 24). Anything smaller, and your words will be illegible.

What not to do

Here’s an example of a slide with fonts that are way too small:

How to do it right

The text size should be at least 28 pt (it is 20 on the above slide). Sometimes you may be able to get away with 24 pt, depending on the particular font (some are just designed larger than others).

Also, keep the font size consistent throughout the presentation. Use the same size font for your bulleted text on each slide (again: 28 or 32 is best). Your title can (and should) be bigger, and it should also remain the same from slide to slide. Too much variation, either throughout the presentation or within one slide, is distracting.

Bottom line: Basic, 28 pt, sans serif fonts are best.