National Play Doh Day is observed on September 16, 2018. Play-Doh is a modeling compound used by young children for art and craft projects at home and in school. Composed of flour, water, salt, boric acid, and mineral oil, the product was first manufactured in Cincinnati, Ohio, U.S., as a wallpaper cleaner in the 1930s.
When a classroom of children began using the wallpaper cleaner as a modeling compound, the product was reworked and marketed to Cincinnati schools in the mid-1950s. Play-Doh was demonstrated at an educational convention in 1956 and prominent department stores opened retail accounts.
Advertisements promoting Play-Doh on influential children's television shows in 1957 furthered the product's sales. Since its launch on the toy market in the mid-1950s, Play-Doh has generated a considerable amount of ancillary merchandise such as The Fun Factory. In 2003, the Toy Industry Association named Play-Doh in its "Century of Toys List". (With material from: Wikipedia)