Looking for today’s fold, I returned to a collection of bookmarked models from my growing collection of Tanteidan magazines:

Made of 4 tetrahedral modules, each with deep tabs along a pair of adjacent sides, you then fold a pair of interlocking preliminary bases as the core.

The modules slot into the core fairly well, making the overall tetrahedral shape – itself composed of tetrahedrons (hence Tetra tetra I suspect)

I used some “fabric paper” from Daiso – it was too soft and does not seem to hold a crease well. I must find another use for the remainder.