Speaker details the science of paint – Daily Union

Serving as this year’s featured speaker at the Fort Atkinson Regional Science Fair, Nicole Mason opened a window into the intersection of science and art: the chemistry of paint.

Mason, who helps develop paints for Handy Art, said that each surface paint dictates a different chemistry.

Practical uses for paint include preventing corrosion, protecting a surface from light or the elements, increasing the energy efficiency of buildings and brightening people’s moods, as in interior design.

“Most times, people don’t want to see what’s underneath,” Mason said. “They want to completely hide what was there before.”

Paint also is a fantastic medium for art, and that’s the area Mason concentrates on as she works on different lines of paint specifically designed to be used by children.

“We make children’s art paint, so there are a whole lot of things we can’t put in because they’ll get it on their hands and wind up eating it,” the speaker noted.

There are 72 different colors in just one of her color lines, each one requiring a subtly different chemistry.

Paint is made up of a resin (the binding substance which causes it to stick to the surface on which it’s painted), the coloring agent, the solvent, additives which serve special functions, preservatives, and ingredients that make all of the other components work together.

The ratio of each component is important. Too much or too little resin, for example, can result in really cakey or really soupy paint which won’t work well.

Color is both an objective description, dictated by wavelength, and a subjective one — slightly different in everyone’s perception.

“Those definitions have even changed over the years,” Mason said. “At one time, (the typical) red tended toward orange, but now it’s more scarlet, the bluish part of red.”

There are individual molecules that go into creating different colors, Mason said.

Earth-tones, for example, tend to use iron oxides (commonly known as rust) with different crystal structures and different minerals thrown in.

Once upon a time, painters typically used lead oxide for their white pigments. Now that scientists know exposure to too much lead can be dangerous, titanium dioxide is generally used instead.

Special effects, such as flurorescence, pearlescence or metallics, can be achieved by adding different things to the paint.

Mason noted that what makes fluorescent colors “pop” is that they absorb more than the normal spectrum of wavelengths, extending into the ultraviolet and the infrared part of the spectrum.

Human eyes can only see the visible part of the spectrum, but the eye interprets this extra energy coming back as a different kind of light, so that these colors appear to be more than 100 percent reflective.

“The energy coming back to you projects back as an intense glow,” she said.

Pearlescent and metallic effects in paint are caused by tiny particles being mixed in. The effect depends on how big the particles are and how it’s reflected back at the people who see it.

Mason then took questions from the audience, ranging from an adult’s inquiries about how to cover over the grey in her hallway to a child’s question about why you couldn’t mix colors to get white.

Mason noted that white reflects all of the colors, while black absorbs all of the colors. So mixing a bunch of different pigments results in a dark color.