We’ve all seen bad PowerPoint presentations with cheesy graphics. They are just not pretty. Considering how important images are to your presentation, you should attempt to use the best graphics you can. Make sure that the images you use are appropriate for your audience.
Using cutesy or cartoony clip art may be okay for a very informal presentation, but in most cases you’ll want to create or acquire good quality images that enhance your message rather than detract from it. (You don’t want your audience marveling at how idiotic your clip art looks.) Also remember that, like words, images are protected by copyright law, so be sure that the images you use are royalty-free or you have paid for the right to use them.
You can insert two basic types of graphics: vector line art and bitmaps. Line art appears the same no matter what size you scale it because the lines are created using mathematical descriptions rather than by a pattern of dots (pixels) as they are in a bitmap. The number of dots in a bitmap (the resolution) determines how it will look at different sizes. If you scale up a low-resolution bitmap, it’s possible to create a really ugly jagged effect.
If you use bitmap graphics, you need to consider whether or not you are creating slides or an onscreen presentation. If you are creating traditional slides, talk to your slide service bureau to find out what resolution they prefer.
For on-screen presentations, you want to size your graphics to work with the monitor you are using. Most laptop screens run at 1024×768, so a full-screen graphic should generally be 1024×768 at 96 dpi to look good on the screen. If you are creating smaller graphics, just do a little division. For example, a half page graphic would be 512 x 364 (1024 divided by 2 is 512 and 768 divided by 2 is 364).
Of course, the bottom line with any presentation is what it looks like. Practice your presentation beforehand to avoid any unwelcome surprises on "the big day."