These blocks can be made with ordinary two part molds. They store in a small fraction of the space occupied by the assembled bricks and they require only a fraction of the materials to manufacture. My method for designing these blocks is described on Delta Block Design Method. I Hope eventually to have a wide variety of compatible systems that include the octet, cube, and truncated octehedra blocks. If you want clearer instructions e-mail me with your snail mail address.
Tessellation Strictly speaking tessellations are tiles that cover the plane without gaps or overlap.
I extend this idea into three dimensions though. I also label tesselations polyhedra that stack to fill space without gaps or overlap. Tessellations, My Blocks Vs Zaks Toys that tessellate have the power to approximate any shape. This page discusses this power and also contrasts my block with a similar toy that does not tessellate as well as Delta Blocks. These are some Escher like Tessellations that I have made.