Before it filled bright yellow cans in preschools, Play-Doh was a putty engineered in the 1930s to scrub coal soot off delicate, non-washable wallpaper. This episode follows Noah McVicker of Cincinnati soap maker Kutol Products, who created the cleaner at the request of grocery chain Kroger, and explains how the post-war shift to natural gas heating and vinyl wallpaper made the product obsolete almost overnight and pushed the company toward bankruptcy.

The rescue came from nursery school teacher Kay Zufall, who tested the failing cleaner with her students, saw them fall in love with it, and pushed back on the McVickers’ proposed name Rainbow Modeling Compound in favor of Play-Doh. From there we cover the 1956 founding of Rainbow Crafts, in-store demonstrations at Macy’s and Marshall Field’s, the 1957 television campaigns on Captain Kangaroo, Ding Dong School and Romper Room, and the chemistry that keeps the dough soft, colorful and mold-free.

• Why the original putty was accidentally non-toxic and safe for children
• Dr. Tien Liu’s fix for fading colors by cutting the salt content
• What surfactants, humectants, borax and a retrogradation inhibitor actually do in the 2004 patent
• The trademarked scent, described to the patent office as sweet, musky, vanilla-like with cherry overtones
• Play-Doh Pete, the Fun Factory, the Fuzzy Pumper Barber Shop, and the path from General Mills to Hasbro and the National Toy Hall of Fame