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10 Unexpected Facts About Ink

by Mike Devlin
fact checked by Jamie Frater

Ink is one of those everyday things we don’t tend to notice, but before our digital age, ink was of paramount importance. With the exception of the spoken word, ink was the only medium to communicate ideas or preserve history for a long time. Ancient inks were made from things like plant dye, burnt bones, and resin. Today, ink technology has progressed to the point where modified printers may soon be churning out human organs.

10 Semen

Various stomach-churning exposes have been done on seemingly clean hotel rooms that glow like the Milky Way when illuminated with a black light. While bodily fluids like blood and urine possess an obvious hue, semen is white and tends to dry clear. You probably see where this is going.

The man who pioneered the use of semen as invisible ink was named Sir George Mansfield Smith-Cumming, because fate exists. He was the first director of the British Secret Service (also known as MI6, the organization that employs James Bond) and a marvelously eccentric man known to prank the people around him by stabbing his artificial leg. BSS agents were so amused by his latest oddball obsession that they adopted the motto “Every man his own stylo.” Fortunately for all concerned, the idea was eventually shelved. While the semen might have been invisible, it did give off an odor, defeating the purpose.

9 The Insane Cost Of Printer Ink

Ink itself is rather inexpensive—one can buy 60 ballpoint pens for about USD $10. According to the Bic website, each of these pens is capable of writing a line over 3 kilometers (2 mi) long. How do printer companies get away with charging such a ridiculous price for an ink cartridge, then? Printer ink currently goes for about USD $9,600 per gallon. At the current rate in the United States, you could by over 2,500 gallons of gasoline for the same price. When pressed for answers, companies like Hewlett Packard tend to point to the high costs of research and development, quality control, etc.

More than anything, the price of printer ink is tied to the industry’s business model. Often called “freebie marketing,” this strategy involves selling one item for next to nothing to boost the sales of a complimentary item. In this case, printers are sold cheaply because the companies who produce them know customers will have to continually buy ink. The same business model is used in the cell phone industry, where pricy gadgets are subsidized on the contingency of two-year service contracts. Printer companies are second to none in maximizing their profit margins. Even those who rarely use their printers are forced to regularly buy new cartridges, as they are programmed to “expire” after a certain set time period.

8 Lemon Juice

One of the more popular science experiments for children is producing invisible ink using lemon juice. The juice is squeezed into a bowl, combined with a bit of water, then painted onto a piece of paper. Once dry, the message vanishes to the naked eye, but holding the paper up to a light bulb will reveal the hidden words.

This is kid’s stuff, the sort of cute little trick that ceases to amuse you right around your seventh birthday or so, but for a man named McArthur Wheeler, this lesson remained viable well into adulthood. In 1995, Wheeler robbed two Pittsburgh banks. Unlike most such criminals, he wore no mask, believing that lemon juice would render his face invisible to security cameras. To his shock but absolutely no one else’s, he was caught just hours later.

7 The Incredible Hulk

That giant green brute of seemingly limitless strength, The Incredible Hulk, is one of the most recognizable characters in the comic pantheon. He made his debut in “The Incredible Hulk #1” in May 1962. However, if you peruse that comic, the Hulk portrayed is not green at all, but tombstone grey. According to co-creator Stan Lee, this skin tone to was ensure that the Hulk was not associated with any particular race. However, there were issues in maintaining his coloration—it couldn’t be kept consistent. The Hulk grew light to dark and back again within the span of a few pages.

The decision was made to make the character green, an ink hue which could be more carefully controlled in printing. Later comics would go on to revisit the grey Hulk as one of the character’s schizophrenic “personas.” Unlike his green counterpart, which was often portrayed as a reckless berserker, the grey Hulk was more cunning but far less powerful.

6 Octopus Ink

Nearly all of the class cephalopoda—which include octopuses, squid, and cuttlefish—can produce a burst of ink. This is used as an escape mechanism. When approached by a predator, they will release a dark cloud of pigment, which serves to disorient long enough for the cephalopod to swim away.

As the name suggests, this substance (which is comprised primarily of melanin and mucus) has been used by humans as ink for centuries. Some haute cuisine restaurants serve squid ink, often as a kind of pasta sauce. Its flavor has been described as a slightly salty iodine. In recent years, it has been discovered that cephalopod ink has medical uses, having been shown to be effective in the treatment of cancer.

5 The Consumer Product Safety Act

In a world where any enterprising eight-year-old can print a semiautomatic rifle in the comfort of his own home, you can hardly imagine concerning yourself with the dangers of ink, but it’s a surprisingly big problem. In 2008, Congress passed the Consumer Product Safety Improvement Act, aiming to protect people from potentially harmful products. One of the laws instituted by the act prohibited the sale or lending of children’s books printed prior to 1985 unless the ink is tested for lead.

Lead is poisonous to humans even in tiny amounts and children are particularly susceptible. Unfortunately, the tests available to analyze older books for traces of lead aren’t exactly cost-effective. Each book runs about USD $300, forcing most libraries and retailers to dispose of their old children’s books.

4 Ashes

Some of the most ancient inks were produced from burnt bones and ash. While the practice has been largely discontinued, ashes are still occasionally sneaked into the press.

Mark Gruenwald was hired by Marvel Comics in 1978. He would remain with the company the rest of his life, serving as a writer, artist, and editor for titles like The Avengers, Captain America, and Thor. Mark was known for his colorful personality, often doing cartwheels down office hallways, conducting practical jokes, and internalizing even the most esoteric Marvel trivia. He died following a heart attack on August 12, 1996 at age 42. He’d made it known that he wished to be cremated and have his ashes mixed into the ink of a comic book. The beloved Gruenwald’s macabre request was honored and a little bit of him was stirred into the ink of an issue of Squadron Supreme, one of the titles that he authored in the past.

3 Termites

Termites are an incredibly destructive form of cockroach known for their affinity for dining on plant material. Often, this happens to be the wood that are homes are made of. The ravenous diet of termites costs billions of dollars in property damage throughout the world each year.

In our attempt to fight this plague, much has been learned about the behavior of these insects, which is largely dictated by the production of pheromone chemicals. For instance, when termites discover food, they excrete a trail of pheromones in order to find it later, much like Hansel and Gretel with their bread crumbs. This tendency can be exploited by pest control technicians by using various substances that mimic the effects of pheromones. One of these is ink from a typical ballpoint pen.

Should you ever find yourself insanely bored and in need of a little gross fun, gather up a few termites, dump them out onto a sheet of notebook paper, and draw a design. The insects will dutifully follow the trail, believing they are on the way to some delicious snack.

2 Blood

Blood generally makes a poor ink. Not only is it somewhat painful to extract, it also tends to oxidize and fade in a relatively short amount of time. That has not stopped people from using it, though. Deposed Iraqi dictator Saddam Hussein was known to have had a copy of the Koran inscribed with his own blood. Several modern artists also use blood as their expressive medium, including Vincent Castiglia, Carina Úbeda, and Jordan Eagles.

The use of blood in ink has also been used as a marketing gimmick. In 1977, when Marvel prepared to publish the first comic book based on the rock group KISS, someone touched upon the idea of adding the band members’ blood to the ink used to print the book. A notary public even stood by to verify the bizarre process. The stunt was resurrected in 2006, when Lionsgate Films decided to use some of lead actor Tobin Bell’s blood to print the movie posters for the torture porn horror flick Saw III.

1 3D Organs

The first 3D printers were produced around 30 years ago, but only in the last few years has the process evolved from mere novelty. Today, 3D printers are used throughout the world and can create nearly anything. There is increasing concern that this technology will be used to create weapons, and working semiautomatic rifles have already been produced. Although the US Department of State ordered the plans removed from the Internet, they likely will have no way to regulate the spread of such media.

Of course, the news isn’t all bad. Soon enough, 3D printers will make it possible to create things like skin for burn victims and even organs. Using cells in a modified ink cartridge, a team at Wake Forest University has even managed to grow a two-chambered mouse heart which they stimulated to beat using electricity. There are even projects underway meant to grow whole human organs made from your own stem cells. Mastering this process would save thousands of lives every year—in addition to doing away with the need for a donor, issues of bodily rejection would be essentially eliminated, as the organ would be composed of your own flesh.

The current technology certainly has its limitations and would need to be vastly improved to produce a viable human organ. While 3D printers are accurate to within scant millimeters, they’re still not precise enough to duplicate tiny blood vessels. San Diego printing company Organovo nevertheless holds out hope, claiming that they will print the first viable human liver in 2014.

Mike Devlin is an aspiring novelist.

fact checked by Jamie Frater