An excellent two-sided UV exposure box
If you want to make your own custom PCBs at home, one method is to paint a circuit board blank with photosensitive material, then expose the portion you don’t want to UV light using a printed transparency. After a process of etching and stripping, the correct traces are generated.
The box itself is constructed out of MDF, white acrylic, and drawer slides to allow for easy insertion and extraction of the PCBs. It looks like an excellent tool, and his instructions would be a great place to start if you want to build your own!