For loose prints this large, the standard archival approach is flat storage, not rolled or vertical storage. Flat file cabinets are the usual best-practice solution, and archival flat boxes are the lower-cost alternative.

For 60×90 cm prints, storing them flat is the safest way to prevent curling, pressure damage, and edge collapse. Keep the storage cool, dry, and dark. Vertical storage for loose large prints is generally not ideal unless each print is well supported.

For smaller prints, archival presentation/storage books with polypropylene sleeves can work well if stored upright with support so they don’t slump.

If you stack loose prints in a box or drawer, using archival interleaving sheets is a sensible precaution, especially if print surfaces might rub.

Airtight storage is harder to combine with practical access. Rather than chasing a fully sealed vertical solution, prioritize archival flat storage and a clean, dry environment; that will do more for long-term preservation. If insects are a concern, avoid food/paper clutter nearby and use well-closed archival boxes or drawers.