Glass making reached its peak at the beginning of the 2nd century AD, with glass objects in domestic contexts of every kind.[1] The primary production techniques of blowing, and to a lesser extent casting, remained in use for the rest of the Roman period, with changes in vessel types but little change in technology.[1] From the 2nd century onwards styles became increasingly regionalised,[1] and evidence indicates that bottles and closed vessels such as unguentaria moved as a by-product of the trade in their contents, and many appear to have matched the Roman scale of liquid measurement.[1] The use of coloured glass as a decorative addition to pale and colourless glasses also increased, and metal vessels continued to influence the shape of glass vessels.[1] After the conversion of Constantine, glass works began to move more quickly from depicting Pagan religious imagery towards Christian religious imagery. The movement of the capital to Constantinople rejuvenated the Eastern glass industry, and the presence of the Roman military in the western provinces did much to prevent any downturn there.[1] By the mid-4th century mould-blowing was in use only sporadically.[1]