A friend of mine spilled coffee down his white polo shirt moments before taking the stage for a presentation. Quick on his feet, he opened his speech explaining his dining mishap. Then went into his material.

This was a great technique: to allow the audience to notice the stain, and then forget it. If he had ignored the stain, the audience wouldn’t have. They’d be thinking: Does he know about it? How’d it happen? Has he been wearing that shirt all day?

Rarely fonts can make a presentation, but if misused, they certainly can ruin a presentation, just like a distracting stained shirt.

Choosing the appropriate font for your slides is important, because the right font will make your text easy to read. But even more importantly, it can keep your audience focused on your message. That’s because a bad font or misuse of fonts are often distracting.

Here are some basic font rules to follow:

1. Keep it simple: Don’t mix font styles. If you find the need to use more than one font, make sure they are complimentary fonts (e.g. – Arial and Arial Bold)
2. Serif vs. Sans-Serif: Serif fonts have  tails on the edge of the letters. By contrast, sans-serifs don’t (sans means “without”). Serif fonts (e.g. – Time New Roman) are commonly used in magazines, because they are easier to read when there is a lot of text. However, on a PowerPoint or Keynote slide, it’s best to use a sans-serif font. Some of the most common are: Arial, Helvetica, Tahoma and Verdana.
3. Don’t capitalize full words: Because it’s like screaming at your audience. Instead, use bold or italics to emphasize a word or thought.
4. Font Size: Try to avoid using a font smaller than 30 point. If you need to reduce the font to squeeze all the text on a slide, chances are you’re using too much text. As an alternative, replace most of the text with a visual that indicates the same message.

Following these steps should keep your audience focused where you want them to be: on your message, rather than on your coffee stain.