British Antarctic Territory Sg 44/58. 64/78 And Varieties

I am having difficulty seeing the watermarks mint stamps of this series. Also differentiating the ordinary paper from the chalk-surface paper. Looking for suggestions. Thanks in advance.


*** Moved by Staff to a more appropriate forum. ***

For your consideration.
Chalky Paper

A highly surfaced, chalk-coated paper introduced
for stamp printing purposes in 1902 and still used
from time to time. It is designed to deter any
attempt at the fraudulent re-use of stamps by
making it impossible to clean off the postmark
without removing the stamp design as well.

Chalky paper can be distinguished from ordinary
by touching it with silver, when a dark, pencil-like
mark is left. An interesting variant of the idea
was the diamond-latticed lines of chalk on the
Arms type of Russia of 1909.

Stamps of chalky paper should not be immersed
in water and great care should be taken when
'floating off'. In catalogues chalky paper is
usually indicated by the capital letter 'C'.

When the letters 'C-O' appear together, it
means the stamp exists on both chalky
and ordinary paper.


- R. J. Sutton 6th edition revised by K. W. Anthony
The Stamp Collector's Encyclopaedia
Published 1966

YMMV but an alternative way of detecting chalky paper is to hold the
stamp to the outside of your (dry) lip - chalky paper will feel cold
compared to ordinary paper.

Regards,
Nick

With practice many philatelists learn to differentiate chalky vs. ordinary paper using a glass. Don't have my Gibbons handy- is this the Antarctic Explorers set? Many crown Agents issues/reprints since the late 1960's were printed on paper so thick and opaque that I've found some impossible to watermark even on a Signoscope. Territories that come to mind include BAT, Bahamas, Barbados, Bermuda, Antigua, and other Caribbean Commonwealth. Over time, I taught myself to sort some of these printings by process of elimination. Not a 100% best practice, but it has helped me at times.

Shermae - yes this is the Antarctic Explorers set. And yes, thick paper indeed.