OSX Yosemite Login Wallpaper

Want to customize the login background of your Mac? Maybe you want to brand it with your company wallpaper or have it match the wallpaper that the user sees when they log in. Well, Apple has made this really simple to do in Yosemite with a single file change.

  1. Get a copy of the image you would like use.
  2. Name it com.apple.desktop.admin.png
  3. Copy it to /Library/Caches
  4. You should probably backup the original in here if you ever want to revert to it.
  5. Logout or reboot the machine.
  6. All done!


OSX Yosemite Default User Wallpaper

Have you wanted to brand your OSX machines for your end user experience, but still let the end user be able to customize their wallpaper? In OSX Yosemite (10.10.*), this is pretty simple to accomplish.
  1. Get a copy of the image you would like use.
  2. Name it DefaultDesktop.jpg
  3. Copy it to /System/Library/CoreServices
All new users (or if you wipe accounts at logout), will now use the image you placed here as the default wallpaper when logging in. At least until Apple decides to change the default wallpaper location, or replace your image.

The benefit of using this method rather than MCX/MDM, is that the end user can still customize the wallpaper to their liking, while you still get to put some branding in right out of the box.