Waldglas

See bohemia.

Waldglas

(from the article `glassware`) ...a continuous survival, probably from late Roman times, of a local type of green glass, a product of forest glasshouses made with potash obtained ...
Found on http://www.britannica.com/eb/a-z/w/4

waldglas

The earliest items of bohemian glass, dating from the 14thC, were made from waldglas, a crude, mould-blown product which used wood as a source of potash for the flux.
Found on http://www.antique-marks.com/antique-terms-w.html
No exact match found