Can I use my own picture as the background?

Yes. On the Image tab, Choose an image opens any picture of your own, and My wallpaper uses your Mac's current desktop picture.

Where is the Blur control?

Under the Image tab, beside the picture swatches. A solid has nothing to soften and a gradient is already smooth, so it is not offered on those tabs.

Do backgrounds work offline?

The catalogue is downloaded as you choose pictures, so offline you see what has already been fetched. One wallpaper always ships inside the app, so a fresh recording never opens on an empty background.

Editing

Background

What sits behind the recording.

Three kinds

The Background panel on the Image tab, showing a catalogue of wallpapers

Image: a picture. Prequel ships a catalogue of wallpapers in a few categories, downloaded as you choose them. My wallpaper uses your Mac's own desktop picture. Choose an image… opens any picture of your own.
Solid: one colour from a grid, or Custom colour for any other.
Gradient: two colours and an Angle.

Blur, shown under Image, softens the picture so the recording in front of it stands out.

Where the picture goes

A background image is copied into the recording's own folder when you choose it. That keeps a recording self-contained: move the folder to another Mac and it exports with the same picture. See Where files live.

Offline

The catalogue is fetched from prequel.sh. Without a connection the picker shows what has already been downloaded, and one wallpaper always ships inside the app so a fresh recording never opens on an empty background.

Frequently asked questions

Can I use my own picture as the background?: Yes. On the Image tab, Choose an image opens any picture of your own, and My wallpaper uses your Mac's current desktop picture.
Where is the Blur control?: Under the Image tab, beside the picture swatches. A solid has nothing to soften and a gradient is already smooth, so it is not offered on those tabs.
Do backgrounds work offline?: The catalogue is downloaded as you choose pictures, so offline you see what has already been fetched. One wallpaper always ships inside the app, so a fresh recording never opens on an empty background.