Way way back in the days, my older brother and I had a toy called the "Strange Change Machine". There were these little squares of plastic, about an inch and half by a quarter inch think. You put them in this little oven thingy, and they transformed into critters like scorpions, spiders and dinosaurs. After roasting your fingers pulling the creatures out of the little oven (tongs? who needs those?) they would harden into playable toys. And then, you put them back into the oven, made them squishy, and put them in a press where you turned a crank and pressed them back into little squares of indeterminate plastic. No doubts that toy was taken from the market to protect little snowflakes, just as were Jarts.
Yet, every time I cut butter for cooking, I think of those little plastic squares that became marvelous fun.