Sun sensitive paper is always fun to have around!
It is summertime and I’m busy keeping my kid busy.
This paper is the classic turns-blue-in-sunlight photo-sensitive stuff I remember from my youth. Shade any part of the paper you do not want to turn blue, and expose it to sunlight. Exposed bits turn blue. You can control the darkening of the blue by allowing the paper to soak up more or less light. Rinse the paper in water to “fix” it and stop the changing.
Tedco 8″ X 10″ Sun Art Paper Kit – 15 sheets via Amazon