In the last two years I have discovered that specific colours of fibers to be found in the paper used for postage stamps belong to different paper mills!What could be seen in the previous scan of the 5c Banco Nacional were the yellow/orange fibers!
The first type I met was the green fiber in the Wiggins Teape papers with the parallel watermark and an asymmetrical paper mesh - the so-called rayado vertical; then the blue fibers in the 1922 Dutch paper used for the 1921 Postal Congress and the 3c José de San Martin - all with parallel watermark and a symmetrical paper mesh.
Quite recently the brown fibers in the Wiggins Teape papers of 1936-1938 - parallel watermark and a symmetrical paper mesh with density 30/20; followed by the same type of fibers again in Wiggins Teape paper this time with a density of 24/22 - the so-called Tela - during the 1941-1945 period!
And right now, the yellow / orange fibers of the Mate Lustroso! A paper of unknown origin with an orthogonal watermark and a symmetrical paper mesh used during the 1940-1941 period!
to be continued ...
