For an airtight to be most effective, the interior dimensions should be an exact match for the coin. If small enough, the capsule will fit into a standard album page pocket.
I use ex British
Royal Mint positive screw sealed capsules for my most valuable modern coins, but they don't have the added advantage mentioned above.
Both types are unsuited for other than modern coins.
Re used
Snap shut airtights do not tolerate being opened more than about 5 times, the friction seal loosens, and risk is that they can fall apart.
Perfectly OK for long term storage, but do not re open. Best used in much the same way as a slab.
From what I can discern, slab manufacturers do not guarantee their products to be airtight, but they would be close to being the next best thing
Edited by sel_69l
08/29/2022 06:19 am