It is perfectly possible to knit or crochet Platonic solids that keep their shape. They need to be worked very tightly or to be stiffened in some other way. When they are not stiffened, all knitted or crocheted objects try to turn themselves into spheres. This is because a sphere has the smallest surface area for any given volume.

The pattern has instructions for making tetrahedra, squares, octahedra, dodecahedra and icosahedra, to any size you want. If you make them small they keep their shape better. The larger you make them the rounder they become.

You can use any yarn. The motifs will all work and fit together. I made mine at cushion size though they are not really cushions because of their 3D shape. I used DK yarns for all.

This pattern was originally published in 2005 on the Woolly Thoughts website.