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The Sound of Science - 'Egg Tempera Paint'


Newt: You're listening to the sound of science on WNIJ. I'm Newt with NIU Steam.

Becky: And I'm Becky here to tell you all about just one of the cool ways science and art come together.

Newt: Paint is typically made from a few base components including pigment, binder, and solvent.

Becky: To get a good consistency there needs to be the right ratio between the binder, which acts like the glue that holds everything together, and the solvent which thins the paint out. Many kinds of paints should be viscous enough to manipulate but thick enough to stay where you want.

Newt: And that final element of pigment is what gives paint its color. Historically, pigment has been sourced from sand, clay, fruits or vegetables and minerals, among others.

Becky: One type of pain that I find pretty interesting is egg yolk tempera.

Newt: Eggs are not the first thing that comes to mind when I try to imagine making paint. But if we break down what's in an egg yolk, it makes a little more sense. Egg yolk contains mostly lipids and proteins. During the drying process, the lipids undergo a chemical reaction called polymerization.

Becky: This polymerization produces the binder component of the paint. So artists would use something small and sharp like a pin to pop the membrane of the egg to access the yolk. They'd separate the yolk from the egg white and combine the yolk with a little bit of distilled water.

Newt: The artists hand grind some dry powder for pigment, combine all the components together and create some art. But why would anyone want to paint with eggs?

Becky: Egg tempera is pretty archival and does not age or yellow like other paints. An artist chooses their medium for variety of reasons. And every type of paint has strengths and weaknesses. Part of art and science is experimentation. And there are even artists today like a Arturo Rivera and MF Dondelinger still experimenting with egg yolks.

Newt: Thanks for that eggs-cellent information, Becky.

Becky: No problem, Newt. I'm all about egg-ducation.

Newt: This has been the sound of science on WNIJ, where you learn something new every day.