The Romans mass-produced glass. This statement requires emphasis because it contradicts the common assumption that mass production is a modern phenomenon and that ancient luxury goods were necessarily handmade in small quantities by skilled artisans serving elite clients. Roman glass was made in those ways too — the cameo glass of the Portland Vase, the intricate millefiori bowls, the delicate cage cups — but alongside and beneath these luxury productions existed a glass industry of genuinely industrial character, producing standardized vessels in enormous quantities for the ordinary consumer market that constituted the overwhelming majority of Roman commercial glass transactions.