Overhead transparencies, also known as foils or just plain overheads, are see-through sheets of plastic you slap onto an overhead projector. In the old, pre-PowerPoint days, overheads (and chalkboards) were the only means folks had to deliver presentations. But even today, with PowerPoint 2007 at your disposal, you may have occasion to print your presentation onto overheads.
For example, imagine you're on a plane, headed for the most important presentation of your entire career. You're settling into a taxi when you discover you left your laptop in the airport terminal. When you get to the conference center, there's not enough time to get your office to email a copy of the presentation and then wrestle it onto an unfamiliar computer. If the conference center has an overhead projector (most do) and you've got a stack of overheads in your briefcase, you're golden.
Printing out overheads isn't a lot of extra work. It involves the same steps you take to create a regular printout, with the following exceptions:
Replace the paper in your printer with a stack of overhead transparencies, available at any office supply store. (You don't need a special printer or special ink.)
Consider printing your presentation on paper first to make sure it looks exactly the way you want it to. It's often easier to spot goofs on paper printouts than onscreen.
If your slides have colored backgrounds, consider printing grayscale or black-and-white ( Printing Slides (One Slide per Page) ...