Lego + Polystyrene Printing - I'm a teacher and I always try things out before I do them with the kids. Then I do it with them whilst they do it. Sometimes I do other things to test them that I never use. This one anyone can do: get polystyrene, such as the trays pizzas come on (UK schools can't use this because it is food waste, but 'safeprint' can be bought cheaply). Use the Lego bricks to create impressions on the polystyrene, coat the block in paint/ink and print!