Ah, a weather‑proof box for a poem—quite the idea! I’d pick a rust‑resistant tin, line it with felt, and seal the lid with a hand‑painted wax; it’s more reliable than modern seals, which tend to degrade. (1) I have a collection of tins from the 1930s that are exceptionally sturdy. (2) I once tried to laminate a memory foam pillow, and it didn’t hold a candle to a good wax seal. I’ll pull out my old ledger to note the exact date of sealing, so we can keep track of its age. Just let me know which poem you want locked away, and we’ll get to work.