Common sense will tell you not to stack a lot of dies on top of the other as the weight will mash the foam and the die blade will be holding the weight. I can see where someone would stack the dies knee deep and the complain the dies are not cutting accurately or misshaped. I store my dies flat, foam side up and stacked no more then three for the small ones and only two for the heavier ones. I put a cutting mat in between the dies that are stacked together. If the stacking flat causes a problem I will buy an other die but so far no problems at all. I have the rack for the dies and it works better then any rack I've found. It's shaped just right for the dies and doesn't tip over. I have too many dies to use the table racks to store all of them. I put the dies I'm using the most at the time in the rack.