Issued in 1969, this 3 Franc stamp from Luxembourg celebrates the 25th anniversary of the Benelux Economic Union (1944–1969), the pioneering regional alliance between Belgium, the Netherlands, and Luxembourg. The striking modernist design by Ootje Treumann features an abstract geometric ribbon combining the national colors of the three member states — red, white, and blue for the Netherlands; black, yellow, and red for Belgium; and red, white, and blue again for Luxembourg. Printed by Joh. Enschedé en Zonen, this issue embodies postwar European cooperation and economic unity.