The slide master is the larger thumbnail at the top in the thumbnail pane.
This opens SLIDE MASTER view, which contains the slide master and master layouts. To work on the slide master, click the VIEW tab, Slide Master. Use the slide master to make global design changes and create exactly the look and layouts you need. When you want to fully customize the design of a presentation, using not only your own background design and colors, but also unique font colors, picture bullets, varied background designs, and customized slide layouts, turn to the slide master.
