Sunprint paper goes through a chemical change when exposed to light. Try this experiment and watch an image emerge:
Select an item of your choice and assemble the package contents in this order: piece of cardboard (bottom), sunprint paper (blue side up), chosen item, acrylic sheet (top).
Expose to the sun until paper turns almost white, from 1-5 minutes, depending on sunlight. Do not overexpose.
Quickly rinse the sunprint paper with water for about 1 minute and dry flat. Watch your image emerge!