How Does an Etch A Sketch Work?

We learned on February 2, 2013, that Etch A Sketch inventor André Cassagnes died last month in France. Here's a look back at his legendary toy.

In 1955, a French electrician named André Cassagnes got an idea for a new toy after seeing how an electrostatic charge could hold aluminum powder to glass. He worked up a prototype for the toy—based on the design of a television screen—in his basement workshop and called it “L'Ecran Magique,” or “the magic screen.” Its joystick, glass and aluminum powder allowed users to draw and erase images and letters with no ink and no mess. Cassagnes sought a patent, put couldn’t pull the money together to get one, so he borrowed from an investor, who sent an employee to pay the fee at the patent office. (The assistant’s name ended up on the patent, and he has often been wrongly credited with the invention of the toy in the decades since.)

Cassagnes’ investor, Paul Chaze, took the toy to several European toy fairs, but it drew little interest. Executives from the Ohio Art Company saw it at the 1959 International Toy Fair in Nuremburg, Germany, and didn’t think much of it at first, either. But they decided to take a chance on the product. [Image credit: The Invisible Agent]

Ohio Art paid $25,000 for the rights to the toy and had their chief engineer, Jerry Burger, collaborate with Cassagnes to perfect it. The company launched the toy in the United States under the name “Etch A Sketch” the following year, just in time for the holiday shopping season.

The Magic Beneath the Screen

When Ohio Art Co. executive William Casley Killgallon brought the toy back from Germany, his 21-year-old son Bill was mesmerized by it. “I was just fascinated,” he told the Toledo Blade in 2010. “I thought, 'How the heck is this working?' I was turning the knobs and just couldn't figure it out.”

And that’s part of the fun, isn’t it? Not knowing how it works? The idea – in a young, fertile imagination – that it might actually be magic? If you prefer to think of it that way, I can’t blame you, but you should stop reading, because here’s what’s going on under the screen:

When you turn the Etch A Sketch upside down and shake it, the inside surface of the screen gets coated with aluminum powder, which will stick to almost anything (mixed in with the powder are small polystyrene beads, which help it flow evenly and keep it from caking).

Also inside are horizontal and vertical bars connected by thin steel wires to the knobs on the face of the toy. A stylus is mounted where the two bars cross, so when you turn a knob, it moves its bar and the bar moves the stylus. As the stylus moves across the inside surface of the screen, it scrapes off the aluminum powder and creates a dark line on the light gray screen, which is just the darkness of the toy’s interior set against the lighter aluminum powder.

To erase their picture, an artist only needs to flip the toy and shake, redistributing the powder over the screen.

Etch A Sketch of Mass Destruction?

In the first season finale of the AMC series Breaking Bad, the protagonist Walter White makes some thermite using the aluminum powder from inside several Etch A Sketches and uses it to melt the lock off of a door he needs to get open. Would that actually work outside of an Emmy-winning TV series?

I’m no Jamie Hyneman, and my girlfriend won’t let me play with explosives in the house (this is, I suppose, her only flaw), so I can’t test this out myself, but it seems pretty straightforward and plausible.

Thermite is made from a metal powder and a metal oxide and produces an exothermic oxidation-reduction reaction, known as a thermite reaction, when heat is applied. This reaction creates extremely high temperatures around a small area and is used for welding in situations where there isn’t enough space for conventional welding equipment (some MIT students also once used it to weld a trolley to its tracks as a prank).

Fuels commonly used in thermite include powdered aluminum, magnesium, calcium and boron. Common oxidizers are boron(III) oxide, silicon(IV) oxide, manganese(IV) oxide and  iron(III) oxide.

Empty a few Etch a Sketchs and you’ve got a small amount of aluminum powder, so all Walter would need is a metal oxide. Iron(III) oxide is easy enough to get (it’s used as a pigment and as “jeweler's rouge”), and an aluminum-iron(III) oxide thermite would easily reach 4500+ degrees (Fahrenheit), enough to melt a steel padlock.

Do 'Close Door' Buttons in Elevators Actually Do Anything?

When you’re running late for work, one small comfort is finding an empty elevator waiting for you at your office building. You scurry inside, and since no one else is waiting to enter, you jab the 'close door' button. The doors comply, the elevator starts moving, and you breathe a sigh of relief.

This is a familiar scenario for many, but it’s also a big fat lie. That’s because most of the door-close buttons in U.S. elevators don’t actually work. In fact, they’re programmed that way.

But before you get ready to send off a strongly worded email to your office building’s elevator manufacturer, you may want to hear why this is the case. When the Americans With Disabilities Act was first passed in 1990, certain requirements for elevators were outlined, such as the installation of raised buttons, braille signs, and audible signals.

The act ensured that someone with a disability would have enough time to get inside, stipulating that elevator doors must remain fully open for at least three seconds and thereby preventing the button from cutting that time short. Some elevator manufacturers took it one step further by deactivating the button entirely.

Since the life span of an elevator is about 25 years and the Disabilities Act has been around for 28 years, it’s safe to assume that most of the elevators in operation today do not have a functioning 'close door' button, The New York Times reports. Only firefighters are able to close elevator doors manually through the use of a key.

It's important to note that there are exceptions to this rule, though. As the New York Daily News noted, New York City elevators are required by law to have working 'close door' buttons, even though some operate on a long delay (so long, in fact, that it calls the button's usefulness into question).

However, you’re in luck if you’re taking a lift (which, of course, is British for “elevator”). 'Close door' buttons are fully functional in most elevators in the UK, according to The Telegraph. A spokesman for the Lift and Escalator Industry Association told the newspaper that not all elevators have the button, but when they’re present, they do work. Again, the time it takes for the doors to shut after pressing the button varies from lift to lift.

While U.S. elevator manufacturers have a seemingly good reason for disabling the 'close door' button, some may question the point of propagating the myth and installing a button that serves no purpose in the first place. In response, some would argue that placebo buttons serve an important psychological function in society.

"Perceived control is very important," Harvard psychologist Ellen J. Langer told The New York Times. "It diminishes stress and promotes well-being."

That’s right: By believing that you’re in control of your fate—or at least how quickly you can make it up to the sixth floor—you’re better off. It doesn’t end with elevators, either. Buttons placed at city crosswalks are often disabled, and the thermostats in many office buildings are rigged so that the temperature can’t be altered (even if the numbers appear to change).

Some might swear up and down that elevator 'close door' buttons work, but this, too, could be your brain deceiving you. As author David McRaney wrote in an essay: “If you happen to find yourself pressing a nonfunctional close-door button, and later the doors close, you’ll probably never notice because a little spurt of happiness will cascade through your brain once you see what you believe is a response to your action. Your behavior was just reinforced. You will keep pressing the button in the future.”

According to The New Yorker, these buttons are designed to alleviate some of the subconscious anxiety that comes from stepping inside a tiny box that's hoisted up some 20 or 40 or 80 floors by a cable: “Elevator design is rooted in deception—to disguise not only the bare fact of the box hanging by ropes but also the tethering of tenants to a system over which they have no command."

So now you know: Next time you’re running late to work, take comfort in the fact that those few extra seconds you would’ve saved by pressing a functioning 'close door' button aren’t worth all that much in the long run.

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What’s the Difference Between Prison and Jail?

Many people use the terms jail and prison interchangeably, and while both terms refer to areas where people are held, there's a substantial difference between the two methods of incarceration. Where a person who is accused of a crime is held, and for how long, is a factor in determining the difference between the two—and whether a person is held in a jail or a prison is largely determined by the severity of the crime they have committed.

A jail (or, for our British friends, a gaol) refers to a small, temporary holding facility—run by local governments and supervised by county sheriff departments—that is designed to detain recently arrested people who have committed a minor offense or misdemeanor. A person can also be held in jail for an extended period of time if the sentence for their offense is less than a year. There are currently 3163 local jail facilities in the United States.

A jail is different from the similarly temporary “lockup”—sort of like “pre-jail”—which is located in local police departments and holds offenders unable to post bail, people arrested for public drunkenness who are kept until they are sober, or, most importantly, offenders waiting to be processed into the jail system.

A prison, on the other hand, is usually a large state- or federal-run facility meant to house people convicted of a serious crime or felony, and whose sentences for those crimes surpass 365 days. A prison could also be called a “penitentiary,” among other names.

To be put in a state prison, a person must be convicted of breaking a state law. To be put in a federal prison, a person must be convicted of breaking federal law. Basic amenities in a prison are more extensive than in a jail because, obviously, an inmate is likely to spend more than a year of his or her life confined inside a prison. As of 2012, there were 4575 operating prisons in the U.S.—the most in the world. The country with the second highest number of operating prisons is Russia, which has just 1029 facilities.

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