You learnt how to improve the design of your slides with the rule of thirds… and you want to display the grid of thirds at the background of your slide. Whether you’re using PowerPoint 2003, 2007, or 2010 the Drawing Guide feature is very useful to do this: It avoid to paste a grid of third that will make more difficult selection of objects.
You have to enable the Gridline feature so that the background of your slide canvas displays a gridline pattern. Since the drawing guides can be repositioned anywhere on the slide canvas, you can position them according to the rule of thirds.
To enable drawing guides, click on an object and then go to the Drawing / Picture Format tab on the Ribbon. Under the Arrange section of the Ribbon, you will find an Align button. When you bring up the Align menu, at the very bottom of it you will find “Grid Settings”, which opens up a pop-up window.
When you check the drawing guide checkbox and click ok, a horizontal and vertical guide will appear on your slide canvas.
Drawing guides can serve as useful rulers to help you align your text and pictures on any slide. You can create multiple guides by holding the Ctrl button and dragging a drawing guide. Using this approach, drawing 2 horizontal and 2 vertical guides can establish the grid of thirds when it is required. If you add one too many guides, simply drag it off the screen to remove it.