How to make a custom background for the PowerPoint slide

To create a slide like one above, do the following:

   1.   Add some shapes to the zone with text and group them (see How to create simple picture designs for PowerPoint slides), for example:

   2.   Right-click on the grouped shapes and choose Format Shape... in the popup menu:

   3.   On the Format Shape pane, on the Shape Options tab, in the Fill & Line group:

• In the Fill section, choose Solid fill and then select Color and Transparency like you prefer:
  
• In the Line section, select No line:
  

In this example, the group of shapes looks like:

   4.   To add a background picture, right-click on an empty slide and choose Format Background... in the popup menu:

   5.   On the Format Background pane, in the Fill & Line group, in the Fill section:

• Select Picture or texture fill
• Click on the File... button and choose the picture you prefer:

Add any other adjustments you would like.

See also this tip in French: Comment créer un arrière-plan personnalisé pour la diapositive PowerPoint.