I made my first rack out of melamine, but it was a disaster from the start, that stuff is HEAVY!

The ones we have now are made of 1 X 4 boards, with some water resistant shower board as the face boards. My husband made the frame from 1 X 4's, used 2 X 2's for the shelf supports, and the shelves themselves are 1 X 4. They are very light weight, immensely strong, and fairly cheap. Our three cost roughly $60 each to build. One is our main rack, it holds a total of 18 tubs of various sizes, most of which have lids. The breeding female rack, which houses my biggest females. And a smaller rack for my husbands newly started breeding colony of 5.

I can get some pictures up if you are interested.

Gale