Book 26, Question 9
How did Play-Doh start as a wall cleaner?
When coal was used to heat many homes, wallpaper got sooty.
A soft, dough-like putty was invented in the 1930s to rub the soot off. Later, homes switched to other kinds of heat and the cleaner stopped selling. Then a teacher noticed that kids loved to model with it. It was renamed Play-Doh in the 1950s and became a toy.