These stunning patterns are art pieces created by spirographs. Spirograph, a geometric drawing device, creates mathematical roulette curves known technically as hypotrochoids and epitrochoids.

It’s the Leeds invention which helped generations of children unleash their creative potential. The Spirograph game was ...

[Tuchman] starts with a quick proof-of-concept using an actual plastic Spirograph toy to make sure it isn’t a totally unworkable idea. Unsurprisingly, the plastic is too flexible to give a ...