To add a border to an object, click on the object to select it.
Click the Line Style button on the Drawing toolbar and select a line thickness for the border.
PowerPoint adds a line around the entire slide object as a border.
INTRODUCTION
To make a slide object stand out on a slide, or to separate it from other slide objects, you can apply a border around the object. Borders are simply lines surrounding the outside of the slide object. You cannot add borders to a shape or WordArt object, but you can add borders to objects such as clip art, pictures, and text boxes.
TIP
Changing the Border Color
To change the color of a border, select the object and click the Line Color button on the Drawing toolbar. Select another color, and PowerPoint immediately applies it to the border.