You will need:
Spray shaving cream into your dish then smooth the surface a bit with a spatula (or spoon, hands, etc).
Use a dropper or paintbrush to transfer the liquid paint to the surface of the shaving cream.
Swirl the colours together to create a marbled effect.
Lay a piece of paper on the surface of the painted shaving cream.
Gently lift the paper off of the shaving cream.
Scrape the shaving cream off the paper with a craft stick or a piece of cardboard.
Set paper aside to dry and repeat with more prints!
You can make several prints each time you add paint to the shaving cream. And you can add more colour to existing coloured shaving cream. When you’re ready for a clean slate, you can either add a new layer of shaving cream to the top (as shown) or scoop the coloured shaving cream out and start fresh.