The Library of Rare Colors

I work with computers
and digital video a lot, which means that I think of color
in terms of light, in terms of amounts
of red, green and blue. Someone who works with print
might think of color in terms of combining inks,
cyan, magenta, yellow and black. A physicist might think in
terms of the frequencies and wavelengths of the light, but there is a very
different way to look at it, through the chemistry and compounds
that make up colors. Inside those buildings,
the Harvard Art Museums, is the Forbes Pigment Collection. – The pigment collection was put together by Edward Forbes, who was
the second director of the museum. He had been buying works of art and in doing so he discovered
that the dealers in Italy were seeing American collectors
as something of a mark. What he decided is that if you understand
what a work of art is made of, what the original materials were
that an artist used, then you can tell original from restoration,
original from fake. And so what he did was
start buying pigments to use as standards for the
analysis of works of art. Knowing that it was visible to the public
meant that I needed to make some sense of what we have as a collection. So what I did was take a color wheel,
open it out, have yellow in the centre and we go along one way to blue,
along the other way to red, and purple at each end. So we have unique colors
along the top, we have duplicates of those colors, which are chemical duplicates,
but not actual color duplicates and then underneath on the
bottom shelf we have the raw material that
makes up the colors above. In effect, what we have are the materials
that make up paint next to each other and then if people look
at the galleries below, they can actually see what artists can do
with these raw materials. If you think about iron oxide for example,
hematite, but as it forms in the earth, those slight additions that the earth adds
into the hematite deposits allow it to look slightly different, so we have 60 different
samples of hematite. Each of those is a slightly different
shade from the other. These pigments are not
used for restoration. We use them only as standards
for analyzing samples from works of art. By analyzing the materials,
we can understand the thinking process and if the artist
is no longer alive, it’s really the closest way to having an
interview with the artist. It’s also great for teaching. We can show the students
how pigments change. They not just fade, but
some pigments darken. It’s like Vaseline, but 80 years old. It doesn’t last forever. Vermillion, red lead will turn black
on exposure to light. You can see how it started. And then other pigments like eosin,
which Van Gogh used a lot, will fade and give an
entirely different impression of what the painting was to what
it looks like now. And so for security, we don’t
have the public in here. Some of the pigments are toxic,
so we don’t want people touching them, playing with them. So pigments are made of mercury, they’re made of cadmium,
arsenic and so on. The oldest white pigment is lead white. It’s made by taking lead metal,
putting it into a container with vinegar. That container is buried in cow dung, so out of manure you get the most
pure beautiful white pigment. That’s been around for
hundreds and hundreds of years. People used it as makeup. Lead white is toxic in the
way that lead is toxic. We have mummy brown. It has been used probably
since the 17th century and it’s made up of Egyptian mummies
that have been ground up into pigment. Indian yellow is an interesting pigment. It’s made by feeding
cows mango leaves only and collecting the urine
and drying the urine. What you see on the screen
depends on the limitations of what the computer screen can depict. So videoing them,
putting them into the digital format, doesn’t replicate the color. There is innovation and people are
developing new ways to depict colors. So for example, Mas Subramanian developed
a blue pigment called YInMn Blue. He discovered it by accident. It’s very stable and it’s the first inorganic
blue pigment that’s been invented for a couple of hundred years. There’s been a new black
that’s come onto the market, which is Vantablack, which stands for
Vertically Arranged Nano-Tube Arrays. What you have is a forest of very tiny tubes
and light will go into that. It will bounce around inside the tubes
and then get issued as heat. It’s a beautiful velvety looking surface
that doesn’t bounce any light back. Chemists produce more and
more pigments every year and I think that we’re going to see
pigments depicting colors that we never thought were possible. Every day somebody is coming in here, taking a pigment out and using it
as a reference. This was beautifully
arranged when I installed it. It took me like four months
of lining everything up and it’s all a little
higgledy-piggledy now, so you can tell that
we use it all the time. It’s not an historic artifact, it’s something that we rely
on to do our work properly. – My thanks to everyone at
the Harvard Art Museums. Pull down the description
for more about them and more about the pigment collection.