On Aug 5, 11:31*am, "No Body" wrote:
* * Does anyone know how the iridescent coating on stained glass is
made, and what the stuff is made of? I'm wondering how to remove
select areas on a piece.

The irid surface can easily and safely be removed with sandblasting or
etching cream. If you want, you can return a full smooth gloss to the
etched parts by fire polishing in a kiln. Pieces done that way can
look delicately elegant.