On May 29, 1954, Vatican City issued a set of three stamps marking the canonization on that date of Pope St. Pius X (1903-1914). The set includes 10-lira (yellow, lake, sepia), 25-lira (yellow, lake, dull violet), and 35-lira (yellow, lake, and gray-black) values.
The vertical design includes a portrait by Guido Freganti of Pope St. Pius in vestments and wearing the papal triple tiara, his right hand raised and extending a blessing. "S. Pio X" (St. Pius X) appears at the top of a column behind the pope. "Post Vaticane" and the stamp's value appear at the bottom of the stamp.
Stamps in the set measure 3 cm x 4 cm, are perforated 13 x 13, and contain the Crossed Keys of St. Peter watermark. E. Pizzi designed the set; the Italian State Printers, Rome, produced it by photogravure. Vatican City issued 280,000 sets, which it withdrew from sale on May 31, 1955.
References:
"Vatikanstaat." 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, 2010.
J. N. D. Kelly, "Pope St. Pius X," in The Oxford Dictionary of Popes. Oxford: Oxford University Press, 2006.
Donald Attwater and Catherine Rachel John, "Pius the Tenth," in The Penguin Dictionary of Saints, 3rd edition. London: Penguin Books, 1995.
Roger Collins. Keepers of the Keys of Heaven: A History of the Papacy (New York: Basic Books, 2009), 455-463, 466-494.