A few different colors of food coloring (I suggest using the three primary colors: yellow, red and blue.
1 can of shaving cream
1 stick for swirling the colors
Steps:
Fill a pan that’s kind of flat with shaving cream, then add squirts of food coloring. Take the stick and “Slightly” stir to mix and spread colors some. Lay paper on top so it just touches the shaving cream. Pull the paper up and squeegee off excess. Let dry and begin with your special letter writing.