I am making several 16 x 22 inch (inside dimension) drawers 12" high to hold electrical and plumbing fittings. Most drawers have 1/4" bottoms but I am concerned about the weight.

How thick would you make the bottom? (I have 1/4" and 1/2" plywood in the shop)
Is there a set of guidelines as to how to determine the thickness of a drawer bottom?

Thanks in Advance,

Jesse Tutterrow