@en|Scanning of a 1925 [[Parker]] advertising for the [[Duofold]] model showing different nib grades. Published on ''The National Geographic''. Retouched by the author for a better sharpness | @en|Scanning of a 1925 [[Parker]] advertising for the [[Duofold]] model showing different nib grades. Published on ''The National Geographic''. Retouched by the author for a better sharpness |