You can add video clips to your project to serve as backgrounds for other content, such as screen titles or clips you’ve shot with a green screen or blue screen. iMovie comes with three types of backgrounds, including solid colors, stylized graphic backgrounds, and animated backgrounds. To use them, you first add the background clip, and then you add other content over it.
For example, you could place a green-screen or blue-screen clip of a friend performing magic tricks in front of the animated background of a stage curtain. Or, if you were creating a movie of a scuba diving vacation, you could place your intro title or credits over the animated underwater background.
To add a background clip:
With your project open, click the “Map, Background, and Animatic” button.
Use the scroll bar on the right side of the “Map, Background, and Animatic” browser to scroll through the backgrounds.
The four animated backgrounds appear first, followed by eight graphic backgrounds and eight solid-color backgrounds.
Drag any background to your project, and release the mouse button when you see a green Add (+) symbol; iMovie inserts the background between clips where the vertical green line appears.
The background is added as a four-second clip.
To change the duration of the background clip, double-click it, type how many seconds you want the clip to last, and then click Done.
To change the background style:
Double-click the background clip in your project, and in the inspector that opens, click the Background button (which displays the name of the current background).
A window showing all the background styles opens.
Move your pointer over any background to preview it in the viewer, or place the playhead (the red vertical line) in a background, without clicking, and press the Space bar. The background plays in a loop in the viewer. You can move the pointer over other backgrounds while another background is playing to see them play in the viewer instead. Click the Space bar again to stop the preview.
Click any background to choose it, and then click Done.
To delete a background clip:
In the Project browser, select the background clip so that it has a yellow border around it.
Press Delete, or choose Edit > Delete Selection.
The Edit menu appears in a light gray bar across the top of your computer screen.