Glass was often the preferred material for storing expensive oils, perfumes, and medicines in antiquity because it was not porous. The small body and mouth allowed the user to carefully pour and control the amount of liquid dispensed. Aryballoi,sometimes called oil bottles, were small vessels used for storing perfumes and scented oils, and were usually made of blown glass. More elaborately decorated and slightly larger examples of these oil bottles were called amphoriskoi and were produced by glassmakers in Syria and Palestine. Aryballoi of this type were also produced in Syria, and in the West.
To learn more about Roman glass, visit our relevant post: How It Was Made: Roman Glass.