Teflon is a remarkable substance. It has the best resistance to chemical attack of any polymer, and it can be used at any temperature between -73 C and 260 C with no effect on its properties. It also has a very low coefficient of friction.
A stale dated warrant is an unredeemed warrant which was issued more than six months prior to the current date. A stale dated warrant is expired and the original instrument is no longer negotiable.
The check was 16 months old, which is what is known as a stale dated check. As I have been told, checks older than 90 days are never supposed to be cashed or credited. When I spoke with the bank manager at Sovereign Bank, he said he was really shocked, that cashing a 16 month old check was, as far as he knew, illegal. The check had originally had a stop payment placed on it.