Dark Green thing? (Booker HP12)

My husband accidentally ordered two huge poppies from the Royal British Legion! So we have decided to display them on our fence and building, the building one will be hard to access regularly so we are trying to make a leaf out of something stiff and durable, plastic perhaps. We need a piece at least A4 size. What might work would be an old estate agent sign that we could cut up and paint green. Any thoughts gratefully received :o)