The Maigelein and other simple optically decorated beakers spread to a wide area already in the Late Middle Ages, and during the 16th century the popularity of optical decoration increased especially in Western Europe. This decoration, made by mould-blowing, refracted and reflected light according to the amount of drink in the vessel, which was pleasing to the eye of Renaissance people. During the second half of the 16th century, optical decoration became common not only in green and blue beakers, but also in colourless glass, for instance, in wine beakers and simple glasses with a shape similar to todayΓÇÖs drinking glasses.
