Police
This picture was done by sketching the design onto a piece of photographic card and then using a lens to focus the sunlight in order to burn the design into the card.
The image was copied from the front cover of the Zenyatta Mondatta album which I had borrowed from a school friend. It was a hot summers day and I was sitting in the garden (with my headphones on a very long extension lead) and mucking about with a magnifying glass.
The triangle is 27cm high and 23cm wide at the base.