There are two different Piezography systems that are now available. Each uses a different ink system and offers different possibilities.
The latest system released in 2016 is called Piezography Pro and uses an 8 or 10 shaded warm/cool ink set with software to produce one million different tone and split tone settings. It also features one pass gloss printing and extremely dark dMax.
Piezography K7 first released in 2005 offers five different ink sets that produce a single tone each. It requires two pass gloss printing, but is also compatible with PiezoDN digital negative if a glossy compatible ink set is chosen. K7 Enhanced adds the extremely dark matte and photo black of Piezography Pro to enhance the dMax of Piezography K7.
You can read more about the Piezography Pro system by clicking here, and read more about the differences between Piezography Pro and Piezography K7 ink sets by clicking here. You can have inexpensive 8.5x11 inch samples printed from your own uploaded images by clicking here