A UV exposure box is an extremely useful piece of kit. It can be used to make proper PCB’s. It can also be used to make other things such as intricate photo etched parts (a subject for another instructable). The trouble is they can be a little pricey for the hobby enthusiast especially if you want the double side type. This instructable outlines the construction of a double sided UV exposure box using the recent generation of high brightness UV LEDs.
UV LED Exposure Box - [Link]