Change the Default Font
Font changes made to the PowerPoint Slide Master do not apply to any new text boxes that you add to slides. They apply only to the placeholders that are present on the Slide Master.
Rather than edit the font type, style and color for each new text box individually, you can change the default font for all new text boxes. Keep in mind to again, use only Web friendly fonts and make the text size approximately 12 pt.
- Make sure nothing is selected on the current slide, by clicking in the area outside the slide.
- Choose Format > Font... from the menu.
- Choose a new default font, size and color from the selections.
- Click OK.