I am planning to use 3/4" plywood (5 ply) for shelves of a shoe rack in my garage. I plan on having 6 shelves each 40" wide without center support. I can get all the shelves out one sheet of plywood if I cross cut against the grain on the outer plies. My question is would the shelves be more likely to bow or sag over time if cross cut instead of ripped, or do the interior plies with adjacent grain balance out the strength evenly for both dimensions? If there are any other reasons not to cut the selves across the outer grain, please do share. I am always looking to learn more. Thanks!