I have found that most of the system-wide folders and configurations have a per-user counterpart. Can someone advise me if this also goes for the wallpapers.

Examples are:

Name               System-Wide                 Per-User

==========================================================================

Applications       /usr/share/applications     ~/.local/share/applications

Themes             /usr/share/themes           ~/.themes

Fonts              /usr/share/fonts            ~/.fonts

Wallpaper          /usr/share/backgrounds      ~/?????

For backgrounds I tried both ~/.local/share/backgrounds and ~/.backgrounds, neither works. I'm still trying to find the per-user area for this folder. If none exist I can stop looking.