Border images?

[John]

Hi, i am looking everywhere to find information about making borderimages.
My  forum has Tinyportal and the border is set to 1.

Now my question is:

Some sites have images instead of a border set to"1". And ofcourse i want this because it looks awesome. But how do i achieve this? I looked into my html books, searched the internet and even looked on the help and support parts of this great SMF site.

But no results.

Could someone help me to get me started?

Thanks a lot