I would like to show you an example of this underprint on a stamp but, as yet, I have been unable to locate one.
The origin of this underprint is unknown.
1872. Unofficial underprint type 67 (over the gum) in black.
a) Vertical underprint, reading upwards
PP222 1d lake-red (SG 43 or G1)
b) Vertical underprint, reading downwards
PP223 1d lake-red (SG 43 or G1)