How do you tell where a 2 dollar bill was printed?

If the bill is dated before 1990, it was printed in Washington DC. For later bills, look to the right of the Treasury Seal. In very small print, there will be a letter and number such as D182 or H7, which indicates the plate position of that bill during printing. If there are the letters FW just before it, the bill was printed in Fort Worth. If not, then it was printed in DC.