During the Spring 2015 semester I taught a class called Being Da Vinci. The movement that I was assigned to teach my students about was the Madonnari. These were street artists who used chalk to create temporary images of the Madonna around cathedrals. This tradition is still continued today and has been evolving.
The idea of the classes was to have the students come up with their own projects and I was more of a facilitator. I came up with some side projects for them to help them to get the ideas flowing and so my students could explore various ways to use chalk artistically. One particularly successful method of experimenting was marbling.
The patterns are the result of color floated on water and then transferred to paper. Marbling is a very old technique and part of its appeal is that each print is a unique monotype.
Students used emery boards and shaved chalk particles onto the surface of water. I used casserole dishes. If you pour two substances of different density in a pan, the material with more density is heavier and will sink to the bottom. Because it is less dense than the water, the chalk floated.
Next students placed a piece of paper on top of the water and picked it up immediately, the chalk stuck to the surface of the paper in its own unique pattern.
Another technique that the kids were interested in exploring was how to make their own chalk. We used equal parts plaster-of-paris and water and then added tempera paint into a cup and then mixed it all up with a Popsicle stick.
The last step was to pour it into an ice tray and let it set for several days. Something we found was that too much tempera paint would not allow the mixture to harden but instead made it stay a gelatinous mush. The first class I did this experiment with (it was my first time making chalk also) the kids got very carried away trying to make the perfect shade of magenta and used up all the red paint. It never hardened into chalk. That was OK, after all, learning what doesn’t work is a necessary step to knowing what does.