Welt Pen was a brand of the Berlin company Schmieglitz & Co. GmbH, which produced several models such as the Wep, Extra and Zep as well as a 'Meisterstück' (also known as 'Dicke Berta' — even larger than a Montblanc 139). Stylistically, some pieces took on elements from the competition, e.g. the cap band of the Waterman Patrician for a ladies-format set. The company suffered greatly from World War II and was liquidated in the early 1950s. Online sources about the company are barely findable, so the knowledge comes primarily from collector circles. There is no connection with the Dutch supplier of the same name.