Applying a New Master to a Slide
You can change a slide’s master at any time. For example, you might want to change a
slide featuring a photo from a horizontal to a vertical photo master.
Any style changes you’ve made to the slide (for example changing the font), are
retained when you change its master, but you can remove the style changes by
reapplying the slide master.
To quickly choose another master for a slide:
Select the slide whose master you want to change, click Masters in the toolbar, and
then choose a different master slide.
To return a slide to its theme default settings:
Select the slide and choose Format > “Reapply Master to Slide.”
To change a slide’s master using the Slide inspector:
Select the slide whose layout you want to change.
Choose View > Show Inspector, and then click the Slide inspector button.
To apply a different slide master, click the slide thumbnail image and choose a master
from the pop-up list.