Most were artisans&colon; glassblowers in Sidon, furriers and dyers in Jerusalem. Most of them were artisans&colon; glassblowers in Sidon, furriers and dyers in Jerusalem. He pioneered many new methods in glass making, together with the glassblowers of Iittala glassworks. Fo learned storytelling from his maternal grandfather and Lombard fishers and glassblowers. A dearth of skilled glassblowers may have also led to the increased use of molds. The ability of heat to produce sound was noted by glassblowers centuries ago. The Blaschka Glass Flowers are still an inspiration to glassblowers today. The glassblowers added uranium to the glass to produce a bright green glow. The contestants on the show comprise 10 glassblowers. Beginning in the late fifth century, glassblowers in the near east produced increasingly larger vessels. Craig tubes can be made by competent glassblowers, and are also available commercially. Glassblowers borrowed technology and techniques from welders. Glassblowers have held on to the old molds. Glassblowers work in the Glass Centre in Leerdam, which is open to the public.