Topic: Polaroid image border containing caption text

Okay so I've got the caption text to position below the main image and for the caption box width to be the same as the image. 
(Thanks to this thread: /forum/viewtopic.php?p=7583)

But I would love to have this caption text inside a polaroid style white image border, one that is thicker at the bottom edge.

Any pointers to get me going in the right direction?