This feature is currently only available in iOS
Whether you've started your project drawing with a satellite image of the property, or have uploaded a site plan PDF, you may want to toggle that off and on as you work.
You'll find the "Background" toggle from within Settings in the top right of the canvas; see the example below.
Toggle off and once hidden, the background will not show up in an export of your drawing. Re-enable it to view.
This can very useful in determining how your work is preceding without a heavy visual in the background.
