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It’s one thing to put your heart and soul into your art. But it’s another thing entirely to put someone else’s heart into your art.

Or... any other body part. And yet, that's what a lot of people have done, for thousands of years. Here are 3 of the ways humans have used bits of ourselves to make things a little prettier.

They’ll make you think twice about what exactly went into that art you're admiring. Earwax, scientifically known as cerumen, is a waxy secretion made up of dead skin cells and different oils produced in the outer ear canal. It serves as a line of defense, protecting against water damage, trauma, and foreign invaders.

So who would have thought it'd help artists make illuminated manuscripts? Despite what the name implies, illuminated manuscripts aren't shining out light. They get their name from gold or silver leaf, which is paired with vibrant painted pictures on handwritten pages.

This art form hit its peak in medieval times, and was practiced both by European and Islamic societies. Once Gutenberg’s printing press spread across the world, though, it dwindled. Until the 15th century, manuscripts were decorated with a substance called glair.

To make it, you had to beat watered-down egg whites into a froth, and then let that stand until it became a liquid. Then, you’d mix in your pigment of choice, and froth it up again. After that settles, you’re good to paint.

Without any other ingredients, bubbles in the froth would leave tiny holes in the surface of your paintings. So that’s where earwax comes in. The oils in the wax prevent the water molecules from bonding with each other in bubble-forming ways, which means nice, smooth paint.

Even when glair went out of style, earwax was also sometimes added to its successor, gum arabic. And the only reason we know it was used at all is advice books! Or at least, the mid-14th century treatise called De arte illuminandi.

Thanks, anonymous author. You’re gross, but clever! But speaking of gross, it turns out human urine has been used for thousands of years, both to make pigments, and to keep the colors in cloth from fading.

It was used with a little plant called woad, the source of Europe's indigo since the Stone. Age. Woad leaves make the same pigment molecules as the plants they used for indigo down in.

India, but not as strong a concentration. Some recipes for crafting balls of woad pigment called for soaking the leaves in urine under the heat of the Sun, while trampling them for 3 days. During all this, a strain of bacteria that’s naturally in the woad munches on sugars and releases the indigo pigment molecules through a process called fermentation.

And urine helps ferment those mashed-up leaves, probably because the ammonia inside helps balance out any acidity in the plant goo. On top of that, natural dyes from things like leaves, berries, or bark can leach out of cloth when you wash it — unless you add a chemical that helps bind the dye, called a mordant. Basically, the dye’s molecules get caught up in the mordant’s molecules, which bind to the cloth.

And turns out, some of the compounds in stale pee, like ammonia and possibly some trace metals, makes it a surprisingly good mordant. In 16th century England, the textile industry used 200 metric tons of urine annually — that’s roughly 1000 people’s pee collected every day! And if you’re wondering how they gathered it all: specialized chamber pots, folks.

But why just use one excretion when you could throw an entire human body into your art? An entire, dried out, crushed up body. Yes, I’m talking about mummies.

Exporting mummies from Egypt to Europe, grinding them up, and selling them as medicine was a big business by the 16th century. In fact, mumia was one of the most common “drugs” found in apothecary shops. But it was also used to make a pigment called Mummy Brown, usually by mixing it with two resins from different trees: white pitch and myrrh.

It came in many shades because there wasn’t a standard technique, like whether to use the entire mummy, or — as one recipe called for — “only the finest muscle.” Plus, mummification techniques varied over the centuries. Different plants, resins, and oils were used during the mummy-making process, and stained the body different shades of brown. Some artists felt like Mummy Brown had a good amount of transparency, and used it in watercolors and oil paint for flesh tones, shading, and glazing.

Others weren’t impressed by its quality, and felt like other brown pigments could deliver the same hues just fine. And nowadays, it’s really hard to find true examples of paintings that incorporate Mummy. Brown.

Even using mass spectrometry to identify the molecules in the paint isn’t so certain. Turns out, a lot of the things used to embalm and wrap mummies were also plain old paint ingredients. The Mummy Brown hype went on for 4 centuries, .

And its downfall started in the early 20th century, as people realized they were painting with grave-robbed human remains, or eventually got grossed out by it. We started actually recognizing the scientific and archaeological value of mummies, too. So thanks, society, for deciding that there are at least some human ingredients that don’t belong in art.

But hey, if you want to use your own earwax or pee… nobody’s gonna stop you. Thanks for watching this episode of SciShow, which is Complexly production. If you want to learn more about all things art, beyond the weird science of it, you can check out one of our other channels: The Art Assignment at youtube.com/theartassignment. [ OUTRO ].