I agree with James on that one. An offcut to them might be a piece of material 50cm by 50cm or larger! It all depends on the supplier.

Another avenue which i never fully explored as I never had to was bus shelter polycarbonate. When panels are replaced they have to go somewhere! Usually in the bin I believe but if you cover up the I love so and so etc and the burn marks from cigarettes they can make for some cheap easy armour panels. Just an idea.