1. Blow out the contents of a dozen eggs. You can find instructions on YouTube. Common tools are a pin, paper clip, and toothpick.
2. Mix Elmer's Art Paste in a tub that's large enough to hold 4 quarts (3.5 liters) of water. Follow the instructions on the box.
3. Prepare the eggshells for decorating by inserting a bamboo skewer (approx. 6" long) into the larger hole on each eggshell and securing it with Sculpey or another modeling clay.
4. Using water, thin the paint to a pourable consistency like heavy cream. Test the consistency by dripping a small amount of the thinned paint into a corner of the tub holding the paste/water mixture. If the paint sinks to the bottom, it's too thick. If it spreads out rapidly, it may be too thin.
5. Drip the paint onto the surface of the paste/water in a set pattern or a random design — it's up to you!
6. Swirl the paint using a bamboo skewer or a wide-toothed comb.
7. Roll each eggshell across the surface of the water until it picks up enough color to cover it completely. You can also dunk the eggshell under the surface and then bring it up to collect the color. Drip additional paint on the surface as needed.
8. Allow the eggshells to drip dry. An empty upturned egg carton works well as a drying rack. Just poke a hole in each egg holder.