Vintner Seal
John Chaucer was a London vintner (wine merchant). Pictured above is the guild seal of the vintners of Bruges (in Flanders). This seal, dated 1407, prominently features a wine barrel and hand drill. The inscription reads: "s[igillum] van den wiinambo[ch]te van brugghe" (seal of the wine merchants of Bruges). This seal is catalogued as F4720 in the Archives Nationales (Paris).

If you want, you can take a look at some more Flemish seals.

London Vintner Seal

This the seal of the Vintners' Company of London (1437). The seal portrays St. Martin sharing his cloak with a beggar. Note the wine barrel at the bottom and the grapevines in the background.