The Vac-u-form, also called Vac-u-former, was a toy made by Mattel

Mattel

Mattel, Inc. is the world's largest toy company based on revenue. The products it produces include Fisher Price, Barbie dolls, Hot Wheels and Matchbox toys, Masters of the Universe, American Girl dolls, board games, and, in the early 1980s, video game consoles. The company's name is derived from...

 in the 1960s. Based on the industrial process of vacuum forming

Vacuum forming

Vacuum forming, commonly known as vacuuforming, is a simplified version of thermoforming, whereby a sheet of plastic is heated to a forming temperature, stretched onto or into a single-surface mold , and held against the mold by applying vacuum between the mold surface and the sheet.The vacuum...

, a rectangular piece of plastic was clamped in a holder and heated over a metal plate. When the plastic was soft, the holder was swung to the other side, over a mold of the object to be formed. Then pressing a handle on the side of the unit created a vacuum, sucking the plastic down over the mold and shaping it to it. When the plastic cooled it solidified, making an impression of the item.

Various molds came with the kit, but almost any small object could be used as a mold.

Because very hot surfaces were easily accessible to a child (or adult) playing with the toy, it probably could not be sold today.