Parker - duofold check blue centennial. Condition nos (new old stock). Complete (with outer box, box & papers). There is conflicting information it seems that parker duofold was introduced to the market in 1921 using the remains in stock of red hard rubber by a parker worker. The leap in quality of parker duofold is instead attributable to 1926 when the first celluloid duofolds were placed on the market. Initially the color was always red, but later colors came later. Duofold is currently one of the most appreciated and distinctive models of the parker production house.