The siting of glass-making workshops was governed by three primary factors: the availability of fuel which was needed in large quantities, sources of sand which represented the major constituent of the glass, and natron to act as a flux. Roman glass relied on natron from Wadi El Natrun, and as a result it is thought that glass-making workshops during the Roman period may have been confined to near-coastal regions of the eastern Mediterranean.[1] This facilitated the trade in the raw colourless or naturally coloured glass which they produced, which reached glass-working sites across the Roman empire.[11]