Tekh

Tekh is a dye made from the ink found in the Hexa, which is a marine mollusc. 
Tekh is a rare material, as the Hexa itself is a difficult creature to catch. There are laws surrounding the domestication of Hexa, and more laws surrounding the production of Tekh itself.  
Once the ink sac is removed from the Hexa, it tends to degrade quickly, and often becomes completely dried and blackened within a day. Thus textile workers must dye any cloth within the day of catch. It is also the duty of the apprentices of these, usually Echaean textile workers to go diving and swimming for the Hexa to begin with, and it is not an easy task. 
The ink produces a rich purple dye that seems to shade indigo in the light, and it is usually used to dye delicate fabrics such as lightweight silks and sheer woven cottons.
It's often purchased by local nobility or whole bolts of cloth are dyed for export. It is considered a sign of incredible wealth to be dressed in Tekh purple, and it is the colour of King Phyrrus' cape.

History & Usage

Everyday use

Dye

Cultural Significance and Usage

It is considered a colour that represents great wealth.

Manufacturing & Products

Textiles

Environmental Impact

Great care is put into the conservation of the coasts and waters where the Hexa live. And there are local laws that state that fishing for Hexa is illegal unless the diver is wearing a special medallion that designates them a textile manufacturer. These medallions have to be purchased and the licenses for them have to be renewed every year.

Type

Biomaterial