The 3-lire (deep violet) stamp shows the interior of the Basilica of St. Clement, dedicated to the fourth pope (ca. 92-99).
The 1-, 3-, 5-, and 8-lire stamps are vertical in design; the other issues are horizontal. The 100-lire stamp is perforated 14 x 14. All other stamps are issued in two different perforation measurements, 14 x 13.5 and 13.5 x 14. The vertical stamps measure 3 x 4 cm. The horizontal stamps measure 4 x 3 cm. All issues are watermarked with the Crossed Keys of St. Peter. All designs are inscribed with Poste Vaticane, the name of the basilica, and the postal value.
Corrado Mezzana designed the set, with engraving by M. Canfarini. The 100-lire value was printed by recess printing; the other stamps were printed by photogravure. A total of 300,000 sets were printed. The stamps were withdrawn August 31, 1957.
Vatikanstaat," in Michel Europa Katalog, band 3, Südeuropa, Unterschleißheim, Germany: Schwanberger Verlag GMBH, 2008.
"Vatican City," in Stanley Gibbons Stamp Catalogue, part 8, Italy and Switzerland, 7th edition, Ringwood, Hampshire, England: Stanley Gibbons, Ltd., 2010.
"Vatican City," in Scott Standard Stamp Catalogue, volume 6, Sidney, Ohio: Scott Publishing Company, 2006.
Filippo Coarelli, Rome and Environs: An Archaeological Guide, translated by James J. Clauss and Daniel P. Harmon, Berkeley, California: University of California Press, 2007.
David Hugh Farmer, Oxford Dictionary of Saints, 5th edition, Oxford: Oxford University Press, 2004.