To be fair, Romans not only mastered glass manudacturing (which in itself pre-dates them), they more or less invented (or however the material was first made du

To be fair, Romans not only mastered glass manudacturing (which in itself pre-dates them), they more or less invented (or however the material was first made during their period) "transparent glass" and - more than that - they invented "pressed glass", i.e. they were among the first to be able to mass produce glass objects, by blowing glass into pre-made moulds, JFYI: http://www.ancient.eu/article/592/ http://www.ancient.eu/article/592/ So, they would have been able to produce glass jars alright and would have probably used (like it was done for wine and amphorae ) "sealing wax" together with cork (and/or some resins): https://vinepair.com/wine-blog/history-wine-transport-8000-years/ https://vinepair.com/wine-blog/history-wine-transport-8000-y... And BTW, they were quite good at making airtight cans, too: https://www.theguardian.com/uk/2003/jul/28/artsnews.london https://www.theguardian.com/uk/2003/jul/28/artsnews.london (though most probably it would have been far too expensive to mass produce them at the time).