How can I create a decorative bar by repeating an image?

[Mathemensch]

I guess the pattern function could help you.
I had a very similar question:

How to use a pattern image as the page background?

I am currently creating some worksheets for exciting, context-orientated lessons. I have an image that I would like to use as the background for these documents. The image is a seamless pattern, so I would like to repeat it in the background instead of stretching it across the entire width. Is there a good way to repeat a background like a cache? So far I am stretching the background to the full height and width of the document. However, as the document gets longer, the quality gets worse and …