Reusing Blu-tac?

Question

I have just found some old blu-tac which is now quite hard and not very useful. How can I make it more plyable again like new?

Answer 1

Mould and rub and warm in it in your fingers and hands.  rather like putty.   usually softens  and becomes usable.

Answer 2

I think if you already used it, you will never make it new again. Perhaps, you will need to buy another.