desktopmacos
I have six virtual desktops and want to change a desktop wallpaper for all of them at once. There is no such option when using System Preferences, so I have to change a wallpaper only for one desktop and repeat this six times.
Is there any way for process automation?
You can set the wallpaper to automatically show images from a certain folder, switching images every X amount of time. This way, your son can put the image he wants in the proper folder and remove the old picture, and the next time it is changed it will choose the only picture there.
Use the + button to select the proper folder, change the stretching rule to fit your needs, and check the box for automatically changing the picture. If you don't set it to automatically change pictures, it will look for the last picture used and show a blank screen when it doesn't find it. You can force the image to be reloaded by logging out and back in, or by executing killall Dock from the Terminal.
The answer is simple (and very Apple-like!).
Simply close all extra desktops until you only have one desktop. (To do this, go to Mission Control, hold down alt and click the crosses which appear on unwanted desktops).
Then change the desktop background for the one remaining desktop.
Now any new desktops you create will inherit the background of that first desktop.
Best Answer
Set the wallpaper for Desktop 1, delete all other desktops, then recreate them. New desktops created always share Desktop 1’s wallpaper.