The template for the IH19 system is a regular hexagon as shown below. None of six sides can be shaped as indicated by the full arrowheads. The template and any tile formed from it have a centre of three-fold rotation symmetry and three axes of reflection symmetry as indicated by the dog pattern.

A single tile forms the translation cluster.

 A section of the tiling formed by the template is also shown below, with a single-tile translation cluster outlined.  The two basic translations are indicated by  the vectors drawn from the highlighted cluster. The tiling has three different centres of three-fold rotation symmetry, one axis of glide and one of mirror reflection symmetry. An example of each  is indicated The tiling symmetry group is p3m1.

No shaping of the template sides dictates that the only tile is a regular hexagon. The tile must be decorated internally to indicate its lower symmetry than that of its regular hexagonal shape. An example is

Four different colours are required to avoid adjacent areas of different tiles having the same colour.

 Author - Tom P McLean --- tom.mclean@virgin.net