I want to put up shelving in my unfinished basement. The walls are studded....2 X 4's with sole plate and tops nailed to floor joists....fiberglass battts and foil covering. My plan is to screw 2 X 4 horizontal ledgers to the studs and attach angled bracing to an upper and lower ledger. I want the floor area unobstructed so I don't want studs standing on the floor. I will make the angle braces from 2 X 4's ripped lengthwise. The braces will be either 12 or 18 inches wide to support plywood shelving. 45 degrees is probably the strongest angle but wire shelving braces are around 60 (?) degrees. Is there are optimum angle for strength but taking less room from the shelf storage space? The shelves will be used to store books, tools, paint cans, etc.