Conversation so far:
when did the new 5 pound come out
The polymer Bank of England £5 note was introduced on 13 September 2016.
why did the bank of england switch to polymer for the 5 pound note
The Bank of England cited that the polymer £5 note would be cleaner, more secure and more durable.
which country first used polymer for currency
Australia was one of the first countries to issue polymer notes, and the first country to adopt the trend. The first banknotes were issued in 1988.

Question: what are the banknotes made of
Self-contained rewrite: what are polymer banknotes made of