Join Date: Dec 2004
Location: Ann Arbor, MI
Bidri technique is characterized by perfectly flat surface. What is described in the Indian paper cited by Kwiatek is an inlay technique with gold/silver/brass wire hammered into incised channels and polished flat with the surface. This was used in the Caucasus and locally known as Zarnishan. Zarbuland is when the same wire protruded above the surface.
What the author describes as Zarnishan sounds suspiciously like Koftgari.
I can see Indian bidri-workers mixing their classical techniques with inlay for additional beauty effects. But to the best of my knowledge, nobody in the Caucasus did bidri work. A very, very different Caucasian technique somewhat resembling bidri ( black/white contrasts) was indeed niello, but again only very superficially.
My guess ( and we all are guessing here) is that we are talking local (linguistic?) variability of terminology. Perhaps ( another wild guess) in India Teh-nishan ( teh-tula?) was a local name of bidri+ inlay of some variety.