John M. writes: I’ve heard that “vinyl” is not good for coins. What does it do to them? And, which vinyl…the covering in albums…the covering in cardboard flips…the plastic flips…the plastic of pocket pages?
Almost all soft vinyl is polyvinylchloride. This chemical breaks down quickly in the presence of light and less quickly in the dark. Eventually the compound falls apart releasing hydrogen sulfide and a greasing oily substance. These will rain havoc on coins. The old cardboard and cellophane flips seem to have preserved coins a whole lot longer than the “modern” vinyl flips.
DO NOT USE any polyvinylchloride near coins as it will eventually destroy them. Use Mylar flips, Cointains (inert plastic shells) or even the old cardboard and cellophane standbys.