I appreciate Judy's reply also about black glue too!
I assume that your kids swirled the shaving creme with those colors then
printed the swirls on their papers by placing the paper on top of the mixture and
gently rubbing. I suggest that you demostrate other ways to print and have
them print the "Starry Night" landscape as well. Make this lesson into a
variety of printing experiences by giving them rectangular sponges for the
buildings, pencil eraser tips, marker caps for the windows, etc. For the mountains,
have them cut their own version out of styrofoam sheets. Attach old marker
caps as handles and print away! Use tempera paint or printing ink. This
lesson can reinforce the concepts of overlapping, silouette, and background,
foreground and middleground as well as capturing the excitement of printmaking!