Roman glass production boomed with the invention of glass blowing, as it allowed for more intricate and detailed shapes. This increased the popularity of glass, which proved the perfect material for the storage of liquids because it is non-porous and translucent.
The iridescence on ancient Roman glass was unintentional, and was caused by weathering on its surface. The extent to which a glass object weathers depends mainly on the burial conditions; however, the humidity, heat, and type of soil in which the glass was buried also all affect its preservation. Whilst the iridescence is only achieved with natural ageing, the light green colouring could be the result of impurities in the glass mixture. Alternatively, substances may have been added to give it a green hue: copper was the ingredient most commonly used to produce green and blue glass.
Roman ancient baby feeders remained similar in shape from 9th century BC to 4th century AD. They often took the form of small beakers or flasks; were portably-sized, and had a handle. They would have contained human and animal milk.