A rummer was a type of large drinking glass studded with prunts to ensure a safe grip, popular mainly in the Rhineland and the Netherlands from the 15th through the 17th century. Rummers lacked the flared bowl of the Berkemeyer and had much thinner walls. The hollow base was built up by coiling strands of molten glass around a conical core. Römers were quite distinct from the Berkemeyers, but both types evolved from the German "cabbage stalk" glasses which were cylindrical with prunts. Römers are usually green in colour and with Berkemeyers were sometimes engraved with images and inscriptions.