Issued to combine with other stamps to pay multiple rates, the 6-cent Washington underwent six renditions, differentiated by a variety of papers, coils, watermarks, and perforations. The rarest 6-cent Washington is the Bluish Paper issue, released in 1909.
As a single stamp, the 6-cent Washington could have paid the three-time domestic first-class rate. Patrons also combined the stamp with other denominations to fulfill large weight and foreign destination rates. By the time the last 6-cent Washington stamps were sold, more than 1.2 billion had been issued.