Lot 81427 – Spanish Colonies, Río de Oro – 1907 4p in se-tenant pair with 3p

1907 4p in se-tenant pair with 3p, three clichés with impression in black on thin paper, two impressions painted black around the area of design to concentrate the light, also a single impression on paper of the 3p value. Important production elements towards Sperati’s final production of the 4p error of colour; a scarce documentation of this issue on which Sperati worked through lithographic process and engraved copper plate.