Lot 50609 – Spanish Colonies, Río de Oro – 1907 4p, a master negative

Spanish Colonies, Río de Oro – 1907 4p, a master negative cliché on film of the 4p error of colour in se-tenant pair with 3p, showing hand painted surround to concentrate the light on the area of design, and, incidentally, the serial numbers on the back of the stamps which have been also transposed; a unique documentation which, together with the copper plate above, evidences the dual reproduction process by which Sperati created the Río de Oro error of colour.