Depends on the bars. Found a box on Amazon a couple years ago for 1oz bars and just about have it full of englehard,jm bars, Aztec, una and the lion, perth dragons, etc... other bars are stacked in a sweet wooden box I got at a garage sale. Graded coins and gold are stored in a much safer location.
Of course you could always vacuum seal the bars and throw them in a shoebox.