Tag Archives: pigment

The impermanence of color: the treachery of entropy

Color seems like an easy, marvelous thing when you get that 64 color box of Crayolas as a kid. 64 sticks of pure color. But, of course, color is complicated. It can be impermanent, difficult to obtain, and toxic. To understand the life and chemistry of colors is to peek under the hood. It’s not what catches your eye, but it’s the heart of the drama.

Many paintings are known to be fading; it’s the newer paintings that draw the most concern. To some extent, the older paintings had probably already faded, but the older paintings also used old tried-and-true methods. The works of Jan van Eyck (1390-1441) are considered to be about as colorful today as when they were painted. Van Gogh’s daisies are fading. Renoir’s red has been digitally re-envisioned to show its pre-faded look.

The 1800s were a boom time of chemistry and industrialization, and the art world participated in this expansion too. 12 elements, including sodium and potassium, were discovered between 1800 and 1810. As Chemistry exploded, and new colors exploded. Mauve, the first synthetic dye, was produced in 1856 from coal tar. Renaissance painters (or their apprentices) prepared their own dyes and pigments (think of those scenes from “The Girl with the Pearl Earring” where Scarlett Johansson is grinding various things); 19th century painters bought paint from chemists. Like the disintegrating trade paperbacks of the early 1900s, when industrialization took over an old process, it was faster and cheaper, but took a while to match other characteristics. Books from the early 1800s are often far more intact than the wood-pulp books that followed them.

Artists like Van Gogh knew the strengths and limitations of their new tools. Van Gogh wrote to his brother, noting that the Impressionist paints “fade like flowers,” so he used the brightest colors he could, doing what he could to counteract impermanence. Even now, not all paints are equally durable; here’s a table for watercolors including such measures.

Today, scientists are studying the precise chemistry that causes fading using X-rays. So far, nothing can be done to stop or reverse the fading; they can only be kept away from light. At least we have the tools to imagine their former glory.

Further reading: Victoria Finlay’s Color is a great read on the chemistry of color without diving too deep technically. I reviewed it on this blog a couple of years ago. This article about the history of oil colors is also really fascinating. And finally, if you’re a chemistry buff, the scientific article about Van Gogh’s fading yellow is open source, and available to the public here.

 

 

Color

Color runs through our lives in many ways– it’s how we pick out the ripest strawberries and cherries, it’s how we put together an outfit, it sets a mood and conveys symbolism. Red is passion and blood, white is purity, blue is serenity or even depression.

Colors are human. We see only a tiny range of electromagnetic waves, and the colors we see depend upon the frequency of that light. The colors of the world are there because our brains and eyes interpret them into the tints we see. Our brains give us that beauty.

Human history is full of color. Painters strive for vibrant shades that withstand the degradation of time. We use colors in food, makeup and clothes. Often, though, we don’t consider the origins of color, and how we obtained these colors throughout history. Many were toxic, such as lead white and red cinnabar (a combination of mercury and sulfur). They chemicals were so valuable and prized that people used them even for makeup. Today, we still use eyeshadow and cherry sodas with crushed bugs, which while slightly icky, is vastly safer.

Although we have many more synthetic compounds and colors, these old colors are still sometimes the best. The titanium white we use today is more opaque and less lustrous than lead white, and some suggest it may not hold up as well over time. Red cinnabar used in Roman art retains its color 20 centuries later. In the last two centuries, we have discovered a whole new range of color compounds with the advent of chemistry and globalization. But our goals are always the same, to stimulate the part of our brain that sees color in wiggles of light.

Colors!