Impress: Focus template background

The Focus template has an interesting effect, in which the first slide
has the appearance of a closed shutter and each slide after it has the
shutter open slightly more. I see that these slides do not have a
background, so the shutter effect is _not_ a background image.

How is this effect achieved?

To clarify, this template has a different "background" on each slide.
As stated in the OP, it's not really a background as it is not using
the Impress background feature, but for display purposes it appears to
the view as a different background on each slide. This is not a custom
animation.

Those images are part of the "master slides". Each of the four initial slides in the template uses a different master slide. The master slides have the images placed behind other content. You can assign whichever master slide you want to each slide (Slide > Master Slide), including the initial four and any others you add, to pick up the corresponding image (and layout of text placeholders).

Mark.

Dotan Cohen wrote:

Thank you Mark! I did not realize that an Impress presentation could
have multiple different Master slides.

Have a great week!