CERN stamp issued by the Swiss postal authorities

On 21 February 1966, the Swiss Postal Authorities issued a 50-centime postage stamp in honour of CERN. The stamp was one of a series of three, the others being in honour of the International Union for the Preservation of Nature and its Resources (10 centimes) (now International Union for the Conservation of Nature, IUCN) and of the fiftieth anniversary of the Swiss Industrial Fair at Basel (20 centimes).
The selected design, by H Kümpel from Zürich, shows the flags of the (then) 13 member states of CERN superimposed on a bubble-chamber photograph. The flags are arranged to represent roughly the outline of the Swiss border.