The template for the IH74 system is any rhombus. All  sides of the rhombus can be shaped, all in the same way, as indicated by the half-arrows. The template and any tile shape formed from it have a centre of two-fold rotation symmetry and two axes  of reflection symmetry as indicated by the dog pattern.

A single tile forms a translation cluster.

 A section of the tiling formed by this template is shown below, with a translation cluster outlined.  The two basic translations are indicated by the the vectors drawn from the highlighted cluster. The tiling has four types of centres of two-fold rotation symmetry, two types of axes of mirror reflection symmetry and two of glide reflection symmetry. An example of each of is indicated. The tiling symmetry group is cmm.

As an example, the following shape can be formed which leads to an interesting black and white tiling.

The associated tiling requires tiles of two different colours, which we choose to be black and white, to avoid adjacent tiles having the same colour.

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