Artisans used a mass of mud and straw fixed around a metal rod to form a core, and built up a vessel by either dipping the core in liquified glass, or by trailing liquid glass over the core.[1] The core was removed after the glass had cooled, and handles, rims and bases were then added. These vessels are characterised by relatively thick walls, bright colours and zigzagging patterns of contrasting colours, and were limited in size to small unguent or scent containers.[7] This early technique continued in popularity during the 1st century BC,[2] despite the earlier introduction of slumped and cast vessels.