You may be referring to earlier posts I made which refer to:
http://uk-hbbr-forum.967333.n3.nabble.com/That site uses this image:
which was uploaded to Photobucket, but any image hosting web service would do. Alternatively you could post the image you want to your forum and then use it's Nabble URL in your CSS code.
The CSS code used for the forum above is:
#forum-header {
height: 229px;
background-image: url(http://i906.photobucket.com/albums/ac268/seahawk-17/ukhbbr/ukhbbrbackground.jpg);
background-repeat: no-repeat;
}
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.