The dough that cleaned off coal soot became a children's toy

In homes heated with coal, the wallpaper was the first thing to blacken. Wallpaper back then was paper that could not be washed with water, so people rolled a dough of flour, water, and salt over the walls to lift off the soot. In 1933, Kutol, a soap company in Cincinnati, began selling this dough in cans as a wallpaper cleaner. It had to be mild and soft, because people rubbed it on the walls by hand. The company became the world's largest maker of wallpaper cleaner.

In 1949, the father who ran the company died in a plane crash, and his son took over. The company made just one product: wallpaper cleaner. After the war, heating shifted from coal to oil and gas, and less soot settled on the walls. Washable vinyl wallpaper arrived too. Wallpaper cleaner was a spring-cleaning item, so orders came in around Christmas, but in the winter of 1954 those orders did not come. Dough piled up in the warehouse, and the company had nothing else to sell. What had disappeared was not the dough but the soot on the walls.

In 1954, a teacher who ran a nursery school in New Jersey read in a magazine how to make Christmas decorations with wallpaper cleaner. She bought a can and took it to her classroom, and the children rolled it, cut it, and squeezed it back together. Made of flour, salt, and water, the dough was safe for children's hands. The teacher called the company and suggested releasing the dough as a product for children. The son who took the call went to New Jersey to see the classroom himself, and the next year he toured schools and kindergartens in Cincinnati to show the dough. Every school asked for more.

The company changed four things. It left out the detergent, added scent and color, gave it a new name, and moved it to a different shelf. At first it came only in white; the next year red, yellow, and blue were added. The name the company had in mind was Kutol's Rainbow Modeling Compound. The name the teacher and her husband offered instead was PLAY-DOH, joining play and dough. In 1956, a department store in Washington put the can not in the cleaning section but in the toy section, and department stores in New York and Chicago followed. As a cleaner it was 34 cents a can; as a toy it was $1.50. The next year, the company gave 2% of sales to a children's TV program, which showed the dough on screen twice a week.

In 1960, the company brought in two engineers to make something for the dough: a mold that, with a light press, pushes the same dough out in many shapes. Instead of making a new dough, it made a tool for using the same dough differently, and that mold is still sold today.

More than 3 billion cans have been sold so far. It entered the National Toy Hall of Fame in the US in 1998, and in 2018 its scent was registered as a trademark with the US Patent and Trademark Office. The registration describes a sweet, slightly musky vanilla scent with a faint hint of cherry, combined with the smell of a salted, wheat-based dough. Today more than 500 million cans are made each year in over 80 countries. The main ingredients are still flour, salt, and water, just as at the start.

Worth adding: this story is often told as an accidental invention. In fact, someone read a method printed in a magazine, tested it in a classroom, and then persuaded the company, and the formula was not used unchanged. The person who made it, the people who sold it, and the person who found a use for it were all different. And the company that made wallpaper cleaner is still around, making commercial hand soap.
The dough stayed the same. What changed was the hand holding it.
Perhaps the use of a thing is decided not by those who make it but by those who use it.