I have been doing quite a bit of Mac OS X Image work lately and have found DeployStudio to be THE best FREE and easy to customise solution for doing this.
One thing i wanted to do was change the default wallpaper for the DeployStudioRuntime.nbi that is created and used as a windows Pre Environment equivalent.
I achieved this by going into the DeployStudioRuntime.nbi folder located on the server at:
I then mounted the ‘DeployStudioRuntime.sparseimage’ file and then navigated to the bellow folder inside the image and replaced the file ‘DefaultDesktop.jpg’ with my custom wallpaper.
I made sure the image i created was a high res image to make it look nicer.