Here is how I store my red boxes:
https://www.target.com/p/two-shelf-...-/A-53184510Each shelf holds 6 red boxes, so 12 total per item.
They come with pegs and I have two stacked on top of each other. Have them on a shelf in a closet and have had no issues with them.
Takes 15 minutes or something to put together once you take the parts out of the box.