Issued in 1967, this set from Liechtenstein honors three prominent philatelists and contributors to philatelic culture. The stamps feature finely engraved portraits by A. Pilch and printed by A. Neef, each commemorating figures who shaped philately in Europe and beyond.

• 30 Rp: Emilio Diena (1860–1941), the renowned Italian philatelic expert and historian.

• 40 Rp: André de Cock (1880–1964), Belgian philatelist and founder of philatelic societies.

• 1.30 Fr: Theodore E. Steinway (1883–1957), noted philatelist from the Steinway family, famed for contributions to stamp collections and cultural heritage.
  The series is prized by collectors for its detailed engraving, vertical layout, and subject relevance, making it an essential part of European philatelic commemoratives of the 1960s.