09/01/2026
After a bit of research, these new old stock Hirota Glass Cold Tea Glasses are even more special than we imagined. The opalescent milk glass looking patterns are made from a traditional Japanese technique called Aburidashi. Rather than etching or painting the patterns, the process infuses bone ash into molten glass revealing the pattern when it cools. Aburidashi is also a historical technique used by ninja agents to write secret messages using invisible ink.
