I am building more cabinets for my garage (it is turning into an addiction) out of 3/4" sides and a 1/2" plywood back. There are fixed shelves at 1", 36", and 71 1/2". Do people usually put a dado into the back piece for the shelves to slide into or just screw directly into the shelves from the back? I have 1/4" dadoes for my shelves to go into the sides but if I do that in the back that is taking away half the material. I could make shallower dadoes but would they be worth it?