Make a batch of super saturated salt water*.
Fill a shallow pan with the salt water. Cut pieces of paper smaller than the pan, any shape you like.
Drip food coloring onto the water and swirl with a toothpick.
|I'm not sure why the red dye looks so metallic in the photos...|
Quickly place a sheet of paper on top of the coloring. When the paper is wet, pick it up and lay flat to dry.
The salt water is much denser than the food coloring, so the coloring floats on the surface, at least long enough to complete this project. Given time, the food coloring will disperse in the salt water.
*Fill a jar part way with hot water. Add some salt and stir. Keep adding salt and stirring until no more salt dissolves (you see the salt sinking to the bottom). Let it sit for a few hours. Then pour off the clear water - the super-saturated salt water solution.