Iso-area chevron corrugation
This is a variant of my chevron corrugation in which every other row of chevrons is reversed, i.e. pointing down instead of up. This makes the corrugation iso-area, i.e. both sides look the same. It also removes the tension which causes the basic version to curl: this variant can be spread as narrow or as wide you like without curling.
Designed and folded by myself, the basic variant of this corrugation was invented independently by Daniel Kwan before me, and his work in turn was based on an industrial design by Charles Hoberman. A model almost identical to the iso-area version (just the angles seem a bit different) is seen in the Paper and Stick movie by Ron Resch which shows models designed in 1960-66.