This beaker is made of Waldglas, or forest glass, so called because it was produced in forest workshops where there were plentiful supplies of wood fuel for the glass furnaces. The characteristic green color of most Waldglaswas caused by iron-rich impurities in the local sand, the major ingredient of glass. Because of the popularity and aesthetic appeal of forest glass, German glassmakers continued to make it even after they were capable of producing colorless glass.
The Getty Museum's glass is unusual not only for its large size but also for the great number and density of its applied prunts or blobs of glass. These may have provided the drinker with a secure grip, even with the greasy hands that resulted from eating without utensils.