The Tenpō Mameitagin was introduced in 1837 as the shogunate's response to a chronic silver shortage, its billon composition representing a dramatic debasement from the earlier Bunsei issues. The "Double Daikoku" variety — identified by two Daikoku stamps rather than one — reflects revalidation countermarking applied at the Edo Ginza to certify pieces for continued circulation after public suspicion about the debased alloy prompted hoarding and refusal.
The Ginza's stamping authority was itself under strain during this period; the Tenpō era reforms were deeply unpopular, and the mameitagin's low silver content was an open secret in merchant communities.
The Tenpō Mameitagin was introduced in 1837 as the shogunate's response to a chronic silver shortage, its billon composition representing a dramatic debasement from the earlier Bunsei issues. The "Double Daikoku" variety — identified by two Daikoku stamps rather than one — reflects revalidation countermarking applied at the Edo Ginza to certify pieces for continued circulation after public suspicion about the debased alloy prompted hoarding and refusal.
The Ginza's stamping authority was itself under strain during this period; the Tenpō era reforms were deeply unpopular, and the mameitagin's low silver content was an open secret in merchant communities.