We recommend storing coins in mylar cases that should not contain PVC. acid-free envelopes are also an option. If you use paper envelopes, make sure they are acid-free and lignin-free
Paper money can be stored in containers made of Polyethylene, polypropylene and polyester, We prefer storing numismatic materials in see-through holders rather than paper envelopes because you do not have to remove the item from the holder to examine it.
A dry, temperature-controlled environment isalso recommended for long-term preservation of coin and paper currency.