These are 2D nets made in Tinkercad that fold up to regular 3D polyhedra, specifically the tetrahedron, octahedron, and icosahedron which all have triangular faces. Printed with a Makerbot Replicator 2 on "Standard", which is .2mm layer height. The nets are made to have .2mm (one layer) base thickness plus another .2mm (another layer) for the faces themselves, which are inset just a bit from the base layer so that fold lines develop naturally. http://makerhome.blogspot.com