Colombia – 1861 « Nueva Granada » 1p, including six items with two master negatives on film, the finer impression annotated as « pas terib. » (not terrible), both with retouches and singularly in red and grey, two negative glass clichés (a rare artifact in the Sperati archive) of which one with comments « pas choisi-fort trop fort »double pellicule- (not chosen-strong too strong-double film) and two trial exposures on photographic paper and designated a & b; a unique lot including matrices which were the foundations for the development of the clichés. No clichés or trial exposures gathered in the postal Museum in Paris or the « Ultimate » collection); this lot proves, as the B.P.A. presumed (apparently no matrices or clichés included in its collection), that Sperati reproduced Colombia before 1939, as one matrix was designated « Alpha », a type of celluloid from teh English brand « Ilford » which the artist used before WWII.