|Note_en=Pubished also on N. 38 (1930-09-21). Advertising for the [[Duofold]] model, showing a set in marbled [[celluloid]], called [[Permanite]], and mentioning [[Parker improvements|47 improvements]]. | |Note_en=Pubished also on N. 38 (1930-09-21). Advertising for the [[Duofold]] model, showing a set in marbled [[celluloid]], called [[Permanite]], and mentioning [[Parker improvements|47 improvements]]. |