Here’s a 1946 page from Popular Science spotlighting the Slinky toy.
It’s always interesting to read vintage copy:
Given an initial shove, “Slinky” eerily and deliberately flip-flops end over end down a flight of steps. It is simply a spring, but it does stunts that made R. P. James, Philadelphia engineer, think of converting it into a toy.
The spotlight also shows how the Slinky can be shaped into patterns. Again, the copy is detailed and ultimately sells the product to the magazine’s more advanced readers:
The flat-coiled strip of Swedish blue steel assumes shapes in almost unending patterns.
It was content like this that really described a product, unlike today’s periodicals which tend to cram a handful or more products onto a page, focusing solely on imagery to promote usage.