- [Arlo] Today we are seeing how scientists can use the molecules of color to detect fake artwork.

- The pigments weren't available until 30 years after he died.

- [Arlo] Restore aging masterpieces.

- Painting is an illusion.

As a conservator, we want to restore that illusion.

- [Arlo] And even, teach us something about what it is to be human.

- As great as technology is, it's still not a good enough substitute for the human eye, and the human experience.

(dramatic music) - But before all that, we need to talk about color.

(upbeat music) Color can be an important aspect of how we perceive the world around us.

Understanding color comes so naturally that most five-year-olds are basically experts at it.

What color is that?

- Purple.

- But when you think about it, color is kind of difficult to explain.

Need an example?

How about that dress that was making everyone go crazy a few years ago?

- This thing is the most irritating thing I've ever seen.

- Sidenote: blue and black, and I will die on that hill.

So to understand more about color, we are talking to Narayan Khandekar.

- So all around us is light that comes from the sun and it's full of color potential.

(mysterious music) (birds chirping) - [Arlo] The light that comes from the sun contains white light, which is a combination of all the colors in the visible spectrum.

Each one of those colors has a different wavelength.

When those wavelengths hit something part of the energy is absorbed and part of it's reflected.

And what is absorbed, we don't see.

What's reflected is color.

- From there, the part that is reflected goes into our eyes where they are detected by specialized cells, and then interpreted as color by our brain.

It is worth noting that a variation in, or the absence of these specialized cells can lead to interpreting color differently.

But this is just explaining how we interpret color.

In order to understand how an object actually reflects a specific wavelength, let's look at how paint works.

- If you think about color, it's very theoretical and it's very difficult to work with in any kind of tangible way.

But what we need is a way to get a work of art to exist in the physical space.

And we do that by creating pigments.

- [Arlo] A pigment is a material that absorbs light and has color, and they can be found all around us, from the leaves on a tree to the rocks under our feet.

Although in the art community, a pigment has a more specific meaning.

- A pigment is a powdered, solid portion of a paint mixture.

- [Arlo] This is conservator Liza Leto-Fulton.

I came to see her to learn more about paint.

- Paint is a composite material of a pigment plus a binder.

This is a synthetic pigment.

- It's so bright.

Can I touch it with my finger or?

- It's cadmium, so it's a toxic material.

- Oh!

- (laughs) Forbidden fruit.

A pigment in older paint, they could come from mineral sources, they could come from plant sources.

They could even come from insects or any natural source.

This one is a bone black, and it's actually made from carbonized bone.

(upbeat music) (record scratches) - [Arlo] Originally, artists had to rely on pigments that could be created from things found in the natural world.

But today, the pigment possibilities are nearly endless.

- There was an explosion of pigments because of the field of chemistry coming into its own.

They understood how to synthesize these pigments in the laboratory.

- [Arlo] Regardless of if these pigments are found in nature or are created in a lab, they follow the same general principle.

We can see this in our food where a combination of pigments produce their color.

Tomatoes gain some of the red color from lycopene, some of the yellow in eggs comes from lutein and some of the blue in blueberries from delphinidin.

These molecules are organic, or carbon-based pigments.

When light hits one of these molecules, some frequencies of light will excite the electrons that form bonds between the atoms, and will be absorbed.

While those that don't have the right frequencies to interact with that particular molecule, will be reflected.

Understanding how light interacts with objects has allowed scientists to create artificial color with very specific characteristics, from different hues, to coatings that can absorb over 99% of the visible light spectrum, making any object that is covered in this coating unbelievably black.

And that's not all.

While studying these properties of light have given artists new and innovative materials to work with, it has also given scientists a different way through which they see and appreciate art: through its chemical composition.

- What we do is take a very small amount of material from the painting, we'll go in with a very pointy scalpel, take a little bit of paint.

And what we'll then do is carry out a series of investigations.

- [Arlo] Researchers like Narayan can identify these pigments, catalog them, and study them.

- Pigments have their own history, each specific pigment has its own history and its own introduction date, and that's important.

So we can add these pigments into a collection, into a library of standards that we have at Forbes pigment collection.

And we can use that information to investigate a work of art.

- [Arlo] Narayan and his team can learn so much about the artwork from this analysis, that they have been known to solve a few art mysteries.

- We looked at some paintings that were supposed to be by Jackson Pollock.

We were able to use the information about the pigments history from our library to say that these paintings were using materials not available to Jackson Pollock.

The pigments weren't available until 30 years after he died.

- [Arlo] But the benefits of chemically analyzing a painting don't end there.

The process can also allow us to rewind the clock to what a painting looked like centuries ago.

The way that a painting looks can drastically change over time.

For this reason, knowing the chemical makeup of the pigments, and having a library of standards to which you can compare them, can help determine how a piece of artwork originally appeared.

Take for instance how scientists were able to digitally scan and chemically analyze the "Mona Lisa."

Giving an idea of how the painting used to look before its varnish darkened.

Similar techniques can and have been used by art conservators to restore works of art with pigment perfect accuracy, allowing them to know the exact chemical composition, or in other words, the color of the paint originally used.

Although, even with all this technological help.

- What you're planning on fixing is just this gap- - Just scratch, there's these little dots here.

- [Arlo] Art restoration isn't a paint by numbers situation.

There are still a lot of hurdles to overcome when restoring artwork.

- So one project we worked on was to use a computer program that we wrote to develop a map of the missing color on some Rothko paintings.

We projected that map onto the paintings and it was all done by computers.

We thought that that would be the answer.

But in fact, it wasn't.

Mathematically, it was as close as we could get, but there were still these artifacts.

There were still colors that weren't right.

There was all kinds of stuff that was going on that needed just a little bit of finessing.

- [Arlo] So despite progress, there are still limitations to what science can do in the service of art, but maybe that's okay.

Maybe that's the nature of art.

- It's not necessary that the average viewer knows exactly what color reds or what color yellow are present in the painting.

What matters to them is the experience.

- Being able to chemically analyze pigments in a painting is incredible.

It not only allows us to verify the authenticity of a work, but it can help us restore it and preserve it for future generations.

But perhaps most importantly, it shows that art is more than just the sum of its pigments.

- Painting is an illusion.

It's not the real thing.

It's about fooling the eye.

You need the human touch in order to be able to do that.

So once that illusion is disrupted by some blemish or a tear, you no longer perceive the illusion.

You're actually focusing on its materiality.

And as a conservator, we want to limit the distraction so that the painting can be appreciated as a whole in the way the artist originally intended for the painting to be seen.

(light music) - Hey.

How are you doing, Arlo?

- Hi, I'm doing all right.

What about you?

- I'm doing okay.

I'm just walking the baby.

Here he is.

How is "Out of Our Elements" going?

- Well, it's done.

The last episode is out.

- Done?

- Yeah, all done.

- Wait.

We actually finished it?

(both laugh) - I'm kind of sad that you weren't in this last episode.

- Well, put me in it.

- Yeah?

- This is red.

(Arlo laughs) Red is the first color babies see, I think.

- No way!

- Make somebody fact check that.

(baby crying) Oh no!

He doesn't like mommy working.

- All right, Caitlin, I'll let you go back to being a mom.

- Yeah, perfect.

See you later, Arlo.

(dramatic music) (gentle music)