Some of the wallpaper / backgrounds I have made over the years for Amiga systems. These are freeware, and you can use them any way you like. (obviously the Amiga brand and Boing Ball is copyright to their respected owners)
You can download them here, they are all in 1920 by 1080 resolution and in JPEG format.
https://aminet.net/package/pix/back/amigangwallpaper - Aminet Download -13.5mb
https://amigang.com/software/amigangwallpaper.lha - This site Download - 13.5mb
If you like my work and if you would like to see other types of Amiga artwork, some of the above backgrounds are provided in a higher format and also some 3d models I'm done over the years are available for just 60p from Leave Reality Studio https://leavereality.uk/product/amigang-art-collection-v1-0/