Are you saying your chips are stored on edge in Mylar holders, in the box?

My reason for asking... As others do, I store my chips in plastic racks. Years ago I noticed some of the chips that were in stacks that had play in them (not tightly in rack) started warping a little. I corrected that by placing pieces of unbleached paper at both ends of each stack in order to fill in any spaces and they have been fine up to this point. I also include one or two thicknesses of paper within the stack if there is a need. I also keep everything in bank vaults where there's little change in temp/humidity... but that's mostly because of my plaques and all.

John