Silly Putty is one of the top-selling children’s toys of all time. However, the ooey-gooey substance isn’t just for kids. Here are 15 facts about Silly Putty that prove it’s a true product of American ingenuity—not just a petty plaything. 

1. SILLY PUTTY WAS INVENTED BY ACCIDENT.

Several individuals claim to have invented Silly Putty, but no matter who's claiming the title of inventor, the underlying story's the same: It was definitely created by accident. During World War II, the government asked chemists to search for a synthetic rubber substitute. One scientist, Dr. James Wright—the man who's most commonly credited for Silly Putty's invention—came close. In 1943, the chemical engineer for General Electric added a bit of boric acid to silicon oil. He noticed that the compound polymerized to form a resilient, flexible material that was almost like rubber. But the substance tended to melt, and it couldn’t hold a solid shape.

A toy store owner named Ruth Fallgatter caught wind of the goo and decided to carry it in her New Haven, Conn. toy store. Eventually, she lost interest in the product. However, a marketing consultant named Peter Hodgson was more than happy to take it off her hands. 

2. SILLY PUTTY WAS PACKED IN PLASTIC EGGS BECAUSE IT WAS EASTER.

Hodgson decided to re-name the goo “Silly Putty” and sell it on his own. But it wasn’t just whimsy that drove Hodgson to package Silly Putty in plastic eggs—it was also timing. Spring was arriving, Hodgson needed a promotional hook, and what would sell a new toy better than a commercial holiday like Easter?

3. SILLY PUTTY WAS FIRST MARKETED TOWARD ADULTS.

Silly Putty wasn’t a hit at the 1950 International Toy Fair. Still, buyers at Neiman-Marcus and Doubleday bookstores picked it up, and before long, the novelty item had received a shout-out in the New Yorker’s “Talk of the Town” section. Thanks to the New Yorker, Hodgson received more than 250,000 orders in three days.

But Silly Putty really took off once the savvy marketing man identified a more lucrative customer base: children. Hodgson created a TV ad campaign for Silly Putty that’s today credited as one of the first commercials for kids. The strategy paid off; when Hodgson died in 1976, his estate was worth $140 million. Today, it would be worth close to $590 million. 

4. SILLY PUTTY PRODUCTION WAS HALTED DURING THE KOREAN WAR.

restriction on silicone during the Korean War meant that Hodgson had to stop making Silly Putty for a few years. Business suffered, but sales picked up once the fighting ended. 

5. SILLY PUTTY IS NOW OWNED BY THE COMPANY THAT MAKES CRAYOLA CRAYONS.

Binney & Smith—the Easton, Penn.-based company that invented the now-eponymous Crayola crayon—purchased Silly Putty a year after Hodgson’s death. (Today, the company goes by Crayola LLC.) The two products are manufactured in the same factory. 

6.  SILLY PUTTY IS A "LIQUID SOLID." 

Drop a ball of Silly Putty and it bounces. Throw it from a roof and it shatters into pieces. Pull it apart, and it stretches. Hit it with a hammer and it keeps its shape. 

7. IT ONCE LIFTED INK OFF NEWSPRINT.

Before Photoshop, crafty kids could digitally manipulate and distort images by placing Silly Putty over newspaper, lifting it off, and transferring the ink onto a new surface. Sadly, this is no longer the case; today’s newspapers are printed using nontransferable ink.

8. IT'S IN THE SMITHSONIAN.

Silly Putty became as historically relevant as Judy Garland’s iconic ruby slippers after a sampling of the brand’s products were added to the National Museum of American History’s permanent collections. According to museum archivist John A. Fleckner, he chose to include Silly Putty because it’s “a case study of invention, business and entrepreneurship, and longevity."

9. IT’S BEEN IN SPACE.

In 1968, Apollo 8 astronauts took Silly Putty to lunar orbit with them in a specially crafted sterling-silver egg. It amused the bored crew, but the toy also had a practical purpose: It was used to hold down tools in zero gravity. 

10. IT’S USED AS A GRIP ENHANCER.

Athletes use Silly Putty to strengthen their grip—a practice popularized by famous football player Raymond Barry

11. IT’S BEEN USED BY ZOOS.

The Columbus Zoo in Ohio once used Silly Putty to make molds of gorilla paws for educational purposes. No word on whether the animals enjoyed playing with Silly Putty as much as their human counterparts. 

12. IT’S MADE INTO ART.

Artist George Horner’s paintings are produced on an unusual canvas: large swaths of Silly Putty. These playful works sell for thousands of dollars

13. IT’S ONE OF HISTORY’S TOP-SELLING TOYS.

According to Crayola, more than 300 million eggs of Silly Putty have been sold since 1950. That’s 4500 tons of goo! 

14. ITS PRICE HAS NEVER CHANGED.

Silly Putty was first sold in 1950 for $1. Today, it retails for the same price—but don’t think you’re scoring the same deal as your parents or grandparents. Silly Putty eggs used to contain 1-ounce lumps. Now, they hold less than .5 ounces. 

15. ITS FORMULA IS TIMELESS.

Modern-day incarnations of Silly Putty range from neon to gold and glow-in-the-dark—a far cry from the peach-colored polymer that first filled eggs in 1950. However, scientists have never bothered to tinker with the basic formula, a mixture of silicone oil and boric acid. It’s remained the same for 65 years, and will most likely stay that way. Talk about a childhood constant you can count on.