How did they make glass in the 1st century CE with such beautiful flowing shapes?
This glass bottle is an early example of glass blowing, which was invented during this time in the Syrio-palestinian region and quickly was taken up by Roman glass makers.
Compare it to the small vessels nearby with the yellow zig-zags, which were core-made, for instance. Core-made vessels, an earlier invention, were formed around a solid core of clay that could be scraped out when the vessel was completed.