In late 1973, Betty Morris and Kathryn Bloomberg set up a small table in Brookfield Square, a suburban mall in Milwaukee, Wisconsin. It was shopping season, and plenty of small businesses were peddling their wares in booths. On the table they placed several pieces of plastic, both large and small, and a toaster oven.
When shoppers walked by, the two arranged for a demonstration. The larger bits of plastic went into the oven. Through the window, people watched them shrivel up. They emerged only a portion of their original size, as though they had been zapped with a shrink ray.
Morris and Bloomberg called them Shrinky Dinks, and over 3000 of them sold in 10 days. They proved so popular that the manager of Brookfield Square asked the two to come back for the entire month of November as well as December. Before long, the partners had sold $50,000 worth of product. By the 2000s, the amount would exceed $150 million.
Against all odds, Morris and Bloomberg generated a fortune by going against the age-old wisdom of never letting a child anywhere near an oven.
Morris and Bloomberg didn’t set out to disrupt the toy business: They were stay-at-home mothers who were looking for craft activities that would keep their Cub Scouts troop engaged. Although several versions of the toy’s origin story exist—one has Morris reading about it, while another says Bloomberg spotted it while recuperating from a broken back—it seems they came upon the idea while thumbing through a magazine, they caught sight of an idea to take clear plastic lids from deli food containers, draw patterns on them, and then shrink them in the oven.
“The lid was going to shrink to charm size,” Morris recalled in 2014. “I thought that if you put plastic into the oven it was going to smell, melt or catch on fire. Finally, I tried it. It worked! I created a small charm size piece. This started my search for larger pieces of this plastic.”
Morris and Bloomberg got the specific plastic recommended by the craft publication and obtained enough to distribute among their Cub Scouts troop so they could make holiday ornaments. The kids were enthusiastic about the trick, which was simple science: Polystyrene contracts when exposed to heat, growing smaller but thicker and more rigid. This is due to the extrusion process during manufacturing, when the plastic is stretched and rapidly cooled to maintain its shape. Heated, it retains its mass but the polystyrene chains return to their original configuration.
“The craft involves tracing an item on shrinkable plastic with permanent felt tip markers, cutting out the traced pieces with scissors and baking in a home oven for three minutes,” the Green Bay Press-Gazette wrote in 1975. “When removed from the oven, it is one-third its original size and nine times thicker.”
Sensing a business opportunity, Morris and Bloomberg ordered 1000 pounds of the plastic from a wholesaler; each threw in $600 as seed money. The duo started selling kits for $2 locally under the name Shrinky Dinks. In addition to the plastic, there were heat-friendly permanent markers for drawing designs along with illustration ideas: pants, shirts, ears, and eyeballs. Morris and Bloomberg enlisted their children—three from each household—to help assemble the kits.
When the women realized shrinking could grow beyond Wisconsin, they entered into an arrangement with the M.W. Kasch Company. The women came up with ideas, while Kasch handled production and distribution. Profits were divided among the parties, and business was booming.
But Shrinky Dinks were about to hit a speed bump with the arrival of Colorforms—and the Smurfs.
After M.W. Kasch began having problems with distribution in 1980, Morris and Bloomberg—operating under the business name K&B innovations—entered into a licensing agreement with Colorforms for a line of Shrinky Dink Smurfs. The blue-skinned, white-capped characters were a Belgian import that had found success as a Saturday morning cartoon and licensing phenomenon. Intrinsically, the tiny forest creatures were also ideal Shrinky Dinks material. Kits based on Masters of the Universe, Rainbow Brite, and Marvel superheroes followed.
But Morris had mixed feeling about the mass-produced and licensed Dinks, which she felt eliminated some of the craftwork out of the process because they were pre-cut. “Colorforms had absolutely outstanding sales with the Smurfs,” she said later. “But I feel that started the decline of Shrinky Dinks. It limited the market to the coloring age. Quite frankly, a lot of adults had been using them themselves.”
In 1989, K&B sold the licensing for Shrinky Dinks to Milton Bradley. But when that company merged with Parker Brothers under the Hasbro umbrella in the 1990s, Shrinky Dinks got lost in the shuffle. “[Milton Bradley] held their licensing rights to Shrinky Dinks for three years but did not market Shrinky Dinks kits,” Morris said. As a result, the brand suffered.
Eventually, K&B reacquired the rights and sold products directly to schools, Scout troops, and other markets. But a retail presence was hard to establish: Like many playthings of the era, their popularity dwindled in the face of video games. Morris, who had bought out Bloomberg’s share and was running the company herself, opted to get out of the exclusive licensing market and instead sell the specific plastic needed for Shrinky Dinks. If a company wanted a non-exclusive claim, they’d have to buy the plastic from K&B.
The plan paid off. Several licensees came on board, and Morris also made craft kits for stores like Hobby Lobby. In 2001, Spin Master Toys offered an Incredible Shrinky Dinks Maker, which used a lightbulb as the heating element and was a safer option for kids, who no longer needed parental supervision in order to use a full-size oven.
The oven, which sold over 10 million units, helped reignite interest in Shrinky Dinks. Today, the brand is sold by Just Play, which acquired it in 2020. In addition to kids, Shrinky Dinks also found a ready audience in the crafts scene. Artisans produce jewelry as well as other trinkets using the method; many of them grew up with Shrinky Dinks. Among the most humble of toy ideas, it’s nonetheless managed to last 50 years—far more than some of the play fads that made a splash before shriveling up.