WebPlus X7: More background help please!

Obviously a senior moment :) Can anyone jog my memory please? I remember how to create the gradient I need for the site background OK but, for the life of me, I cannot remember I had this to the background of all pages.

I have tried through site properties but with no luck. I have done this in the past in X6 but it now slips my mind.

Thanks to all/any input.

Graham