Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I changed the login background in Snow Leopard. Each time I start up the computer, I see my nice new login background, but after I log in, I get the same old Aurora image for about a second before the regular finder wallpaper replaces it.

My finder wallpaper is stored on an external disk. I think that the Aurora wallpaper is shown by default because it takes a second for the system to find the wallpaper on the external drive.

It seems likely that there is a preference for a default wallpaper if Snow Leopard can't find the wallpaper used during the last session.

Does anyone know where this preference is stored?

share|improve this question

The default desktop wallpaper is stored as /System/Library/CoreServices/DefaultDesktop.jpg. You can replace this file to change the default wallpaper.

share|improve this answer
I tried that, and it changes the login background. But, I get still the the old Aurora background for a second after logging in, before the finder appears. – Andrew Swift Nov 28 '10 at 11:14
Hrm, interesting. I wonder if that background is hard-coded somewhere, or maybe it gets copied into new profiles as the default wallpaper. It would be worth investigating if you create a new user account now, if that account experiences the same thing or gets a flash of your new login background. – Stephen Jennings Nov 28 '10 at 22:43
Oh, neat. It didn't occur to me that they would hardcode a specific wallpaper name. – Stephen Jennings Nov 30 '10 at 8:48
up vote 1 down vote accepted

I don't have the real solution, but Stephen's comment gave me an idea for a workaround: the image that is displayed for a second is /Library/Desktop Pictures/Aurora.jpg (I swapped it for another image with the same name and the new image appeared).

I assume that this address is hardcoded somewhere else as the "if the previously specified desktop image is missing, use this one" image.

By changing the login background in Terminal to this address, I can swap out Aurora.jpg when I want new login backgrounds, and there will be no flickering image between the login image and the finder background:

sudo defaults write /Library/Preferences/ DesktopPicture "/Library/Desktop Pictures/Nature/Aurora.jpg"

share|improve this answer
Though I doubt any application relies on the digital signature of /Library/Desktop Pictures/, changing that might break some signature, or some BOM checksum? – Arjan Dec 5 '10 at 15:41
So far it works fine... if I ever have a problem I'll come back and edit this page. – Andrew Swift Dec 6 '10 at 12:44

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .