Lesson 2 – Clean Slide Design improves presentation effectiveness

A common complaint of audiences is that they can’t see what is on the slide because the color choice, font choice or font size is making the slides unreadable.  These are all problems with slide design and in today’s lesson, we’ll cover some ideas that will help you create a design for your slides that is clean and easy for the audience to see.

Select colors that have enough contrast
The reason that some slides are unreadable is that the colors that have been selected do not have enough contrast with each other.  If there is not enough contrast, the colors blend into each other and can’t be easily distinguished.  In today’s resource below, I’ll give you a tool that can measure if two colors have enough contrast.  Can you make this simple by always choosing a certain background?  No, unfortunately it isn’t that easy.  There is no research that shows whether light or dark backgrounds are universally more appealing to people, so we have to do the work of figuring out whether our colors have enough contrast.  Some combinations that usually work well: dark green, dark purple or dark navy with white or yellow text; light blue, light green, light grey or white backgrounds with black, dark navy or dark green text.

Select an easy to read font
Research shows that sans-serif fonts are easier to read when projected than serif fonts are.  Serif and Sans-serif are somewhat technical terms, so let me explain what this means in practice.  A serif font has extenders (called serifs) on the letters and is best for print purposes where the extenders help guide the eyes from one letter to the next.  The most common example of a serif font is Times Roman (this sentence is in Times Roman font).  A sans-serif font does not have the extenders and is best for projection because the lower resolution of projected text causes problems is reading serif fonts.  The most common sans-serif fonts are Arial and Calibri, the default fonts in PowerPoint 2003 and 2007 respectively (the text in these lessons is in Arial font).  By choosing a sans-serif font, you ensure that text will be easy to read for your audience.

Make the text big enough to be easily seen
I’m sure you’ve heard a presenter say “Now I know you can’t read this at the back” and like me, you want to shout back to them “Then why didn’t you make it big enough so we could see it back here!!”  So the real question is, how do we know if the font size we have selected is big enough?  I’ve done the calculation using visual acuity standards (the standards for measuring your vision at an optometrist) and the standards for readability of road signs and have come up with a table for determining how big a font you need based on the distance of the last row from the screen (the link is in today’s resource section below).  While the table is the full and complete answer, many of you want the quick answer.  So, if you are looking for a quick rule of thumb to apply, I’ll suggest that if you use 28 point or bigger fonts, you will usually be OK.  You can probably get away with 20 or 24 point for a label on a graph or diagram, but the easier it is for your audience to read any text on your slides, the better they will understand your message.

Establish standards on the Slide Master
The best place to set your colors, fonts and other slide design elements such as logos is on the Slide Master.  This will save you a ton of time in formatting each slide individually and it will keep the design consistent for your audience.  I suggest you start by designing your Slide Master before you start adding any content.

After you have structured your message with the ideas from Lesson 1, design your slide look by selecting colors and fonts that make your slides easy to see.

To learn more, I recommend these resources

When you want to know whether your color choices have enough contrast, don’t guess, use the two international standard tests for color contrast.  I’ve created an easy web-based Color Contrast Calculator that you can use by clicking here.  You’ll see it has instructions on how to use it and even has suggestions if your color choices don’t pass the tests.  The second resource is the full table that shows how to know if your font size will be big enough based on the size of the screen and the size of the room.  You can download the table in PDF form by clicking here.  Follow the instructions on how to use the table in order to make sure the audience will be able to read your text.  Both of these resources allow you to make educated decisions about aspects of slide design without having to ask a designer or guess whether your choices will work.

By Dave Paradi

Dave Paradi has over twenty-two years of experience delivering customized training workshops to help business professionals improve their presentations. He has written ten books and over 600 articles on the topic of effective presentations and his ideas have appeared in publications around the world. His focus is on helping corporate professionals visually communicate the messages in their data so they don't overwhelm and confuse executives. Dave is one of fewer than ten people in North America recognized by Microsoft with the Most Valuable Professional Award for his contributions to the Excel, PowerPoint, and Teams communities. His articles and videos on virtual presenting have been viewed over 4.8 million times and liked over 17,000 times on YouTube.