Vertical reverse print pair - postage stamp catalog no. 40 I NKb, Bizone

This vertical sweeping pressure pair comes from the American and British zones. It is the postage stamp "Arbeiter" from 1948 with a ribbon print. The upper stamp has the label upside down, the lower one normal. Catalog no. 40 I NK b.
When the DM was introduced in the three western occupation zones on June 21, 1948, the necessary quantities of postage stamps had to be made available at short notice. For this reason, the Oberpostdirektion were commissioned to provide joint editions of the second control council series with a black letterpress imprint "Posthörnchen between ribbon strips". From this overprint there is, among other things, this interesting pair of reverse printing stamps. This is the dark blue-gray 12-pfennig postage stamp as a vertical pair, with an inverted print on the top and a normal print on the bottom.