1935 (November) Experimental "wet" printing on damp paper, in a effort to improve line and colour definition. Single watermark.Red brown.
1936 (Feb) further experimental printing with damp paper, but on the wrong side which results in the watermark being both inverted and reversed. Single watermark. Red brown.
1936 (June) Change to multiple watermark. Colours in this printing include Red brown. Deep red brown and the rare Purple brown.
1936.Of this particular official, only four mint copies are known to exist, and no used copies have ever been found. This image is just used as a example.
1936 (March)
1936 (July)