|Note_en=Scanning of a June 1926 [[Parker]] advertising for the new [[Duofold]], promoting unbreackable barrel in celluloid (named ''permanite''). Published on ''The American Magazine''. Retouched by the author for a better sharpness. | |Note_en=Scanning of a June 1926 [[Parker]] advertising for the new [[Duofold]], promoting unbreackable barrel in celluloid (named ''permanite''). Published on ''The American Magazine''. Retouched by the author for a better sharpness. |