Karl Wiedmann worked for WMF in the 1920s to 1930s. Karl Wiedmann developed MYRA-Kristall with its beautiful iridized surface. This was launched in 1926 along with IKORA-Kristall, with its coloured inlays and patterns of bubbles. Both types of glass were very successful and continued in production for about ten years, until production of art glass virtually ceased in Germany prior to the War. Ikora glass was made for about five years after the war, but on a smaller scale. Karl Wiedmann is listed at artnet.com.
Myra is the name given to the iridized glass produced by WMF from 1926. Based on the same techniques used by Tiffany and Loetz, the glassmaker Karl Wiedmann brought it to the production stage after experimentation at the Zwiesel glass school. The glass is a crystal formulated with silver nitrate instead of lead. The silver gives the glass a rich translucent amber color, but more importantly, it comes to the surface when reduced in the oven.
Ikora comprised literally hundreds of shapes and colour combinations, and was in production between 1928-1951. Although most 'Ikora' was factory-produced the process of production purposefully left much of the finish to chance, so no two pieces are ever identical.
The emphasis was on production rather than on individual creators, and consequently WMF glass was never signed: a simple factory label was deemed sufficient. These were team work factory designs, although Karl Wiedmann is credited with many of them.
Collectibles by Karl Wiedmann
Confusion occurs sometimes with other manufacturers who used the same type of techniques of powder decoration between glass layers. Loetz made a type of glass during the same period called Schaumglas, or "foam glass" which includes colour and numerous small air bubbles and is often mistaken for WMF.