New backround

[virus--x]

Hello!  I gladly another background will use.  I thought there of a picture.  How Mach I that? 

[Joachim Müller]

edit themes/yourtheme/style.css, find body style definition and add the background-image attribute to it. English css tutorial: http://www.w3schools.com/css/css_reference.asp
As you appear to be German, recommended reading is http://de.selfhtml.org/css/eigenschaften/hintergrund.htm#background_image
Please understand that this board basically deals with coppermine in general, but not with particular aspects of web page design (html and css). We can provide some hints, but the actual work has to be done by you if you don't want to use the themes that come with coppermine, but have a customized theme. Using a background image is not recommended though, as it rather distracts viewers from the pics in your gallery.

Joachim