That is simply a series of smaller images, not one large background image.
Background color is white.
Then load a header image: h**p://i3.answers.microsoft.com/Partner/MasterPages/AnswersV2/images/bg.jpg
Then white content area is added on top. In CSB we use Tables to do this last step.
You can add a code to stop repeat as defined here:
h**p://www.samisite.com/backgrounds/id6.htm