This magical activity is based on a photographic process: cyanotype. The child creates scenes on photosensitive paper using opaque patterns. When exposed to sunlight, a negative of the patterns is produced on the paper. Then, all that’s left to do is rinse the paper in a clean water bath and watch as the creations appear on the blue background! With 4 felt-tip pens to transform 4 pictures into colourful underwater scenes.