be not worth the paper it's printed on

be not worth the paper it's printed on

To be useless, unimportant, or insignificant. Oh, that memo is not worth the paper it's printed on. You know the boss is going to completely change her mind about it in a few days anyway! Due to the recent hyperinflation, the nation's currency is now not worth the paper it's printed on.See also: not, on, paper, print, worth