Place a piece of thick white paper on top of the marbled shaving foam in the tray and gently push down to ensure the foam covers the whole surface of the paper. Remove the paper from the tray and use the ruler or scraping stick to scrape off all of the excess shaving foam. This should leave a marbled effect from the paint on the paper!
Repeat steps 1-3 until you have enough marble paper to cover your box with. Leave the papers to dry.