The Argentina 1935-51 Definitive Series
A Stamp Collecting Blog Dedicated to one of the Most Interesting Series of the 20th Century
Saturday, December 6, 2008
There are two types of NGR
Thanks to the listing by Dario Bardi, I learned of two directions of this paper, which I have verified. Here is a comparison scan.
NGR-LR, longer grooves horizontally left to right
NGR-UD, longer grooves vertically up and down