The final stage of oven-drying the tea leaves, which were then packed in chests lined with lead foil to preserve the aroma.
After the tea leaves were harvested, sorted and blanched, they were thrown for a few moments onto iron plates placed on top of ovens. Light wooden tea chests were also made for them, lined with a thin layer of lead that helped them retain their aroma.
China Trade paintings were made for the export market from the late 18th to the mid-19th century.
Joana Belard da Fonseca, in the Catalogue Portuguese Presence in Asia, Museu do Oriente, 2008, p. 161