I try to identify my "Sitzende Helvetia". I have a Michel Mitteleuropa 2016 and an old Zumstein Europa 1981 (German language is not my strong point).
It seems there are there different periods, all of them with K 11 3/4:
- 1862 - white paper with control-mark 1
- 1867 - white paper with control-mark 1 (different colors and values)
- 1881 - fiber paper with control-mark.
In Zumstein I found for 1881 - blue and red fibered paper (identified on my stamps).
Still I cannot say that I can clearly identify these 3 different periods on identical values and colors, especially on used hinged stamps.
A good example is 50c used stamp. The date is 12.12.81. The paper, in my opinion, is more yellowish, and rather thin but the control mark is visible. I can see the red and blue fibers in the paper using a basic digital microscope. In Michel there is no information about blue and red fibres for 1881.
How can I easier identity these 3 different years of Sitzende Helvetia?
Thanks for your answers!