We called this painting with crystals, because that is what it looks like! We stirred Epsom salts to a little warm water until dissolved and then mixed in water color paints.
We painted as we normally do. When the paintings were dry, little crystals were sparkling up at us. The crystals were bigger on the places the paint on thickest.
After awhile the crystals did get powdery and turn to dust, but it was lovely having them while they lasted.
To make your own Crystal Paintings:
Paint (or food coloring)
jars or muffin tins to hold paint in
1) Mix about equal parts epsom salt to warm water. You can mix them into jars, bowls or muffin tins, anything that you want to use as holders for the paint. 1 teaspoon of each or however much you need to make)
2) Add a little salt. (for 1 teaspoon Epsom salt add a pinch of table salt). Mix until the salts are dissolved.
3) Add watercolor paints or food coloring to get desired colors.
4) Paint as you would regular watercolors. Let dry and enjoy!
*I have not tried it yet, but I suspect that replacing the salts for borax would also make some amazing crystals.