Austria, 2005, 100 c. 14. multicoloured

Catalogues:
Michel: 2520, block 27
Scott: SS 1990
Stanley Gibbons: MS2754
Yvert et Tellier: block 32

This stamp is the first of its kind in the world: the face in the background is made up of microscopic chemical formulae for the steroid (art screen composed of enantiomers of the steroid).

Plots: Djerassi Carl