Six Coasters Decorated with Tilings

thingiverse

Here are six mats or coasters about 9 cm across. They are decorated with representations of the tiling of an array of 68 squares with 3 sets of 4 identical polyominos - 4 heptominos, 4 hexominos, and 4 tetrominos. The patterns have the symmetry of 6 of the 10 two dimensional crystallographic point groups. Squares representing the sets of polyominos are covered with squares, hexagons, crosses or circles to make the patterns. Look for 2 and 4 fold rotation axes and also lines of reflection symmetry that pass through the center of the mats. OpenSCAD code that created the holders is included.