The small beaker of pale-green tinted glass moulded all around with fifteen diagonal bands of seven raised bosses which continue into the kick-in base.
Numerous examples of these have been found in excavations and are referred to in the Netherlands as Knobbelbeker (knobbly beaker) or in Germany as Warzenbecher (wart beaker).
Waldglas or ‘forest glass’ was made throughout central and northern Europe and was usually fluxed with potash derived from the ash of the wood that fired the furnaces. The pale-green almost aquamarine tone is due to traces of iron impurities in the sand from which it is made.
The form evolved from earlier spiked German vessels.
Barbara Wirth Collection
For a very similar examples see: Rückert, Rainer, Die Glassammlung des Bayerischen Nationalmuseums München, Hirmer, München, 1982, Vol. I, no. 283