Pablo,
the printing in other printing processes might give the same result, but on the other hand printers use different types of paper for different printing methods. So the paper used here for the 45c might indeed be a different one from that used for the offset-litho printed stamps in the 1951-1963 period!
José Merlo having contact with the Casa de Moneda reacted to a remark of mine:
Studying the 1952 Evita Peron definitives we have both at hand! The uncoated version for the lower values [except the recess printed 45c!] and the coated version for the higher values [1p upwards]. All printed in photogravure but for the 5p, 10p, 20p and 50p that are in recess.
I regret not to be in accordance with you. In Eva Perón first issue lower values are in rayado vertical --not asymmetrical for me-- and and in same paper but coated up to the 3p. 5 to 50 pesos values are printed on tela tizado, of which are two versions: thick and thin, the last one called "aceitoso" because its transparency. I understand this was so as as you should know, overbeaten fibres gelatinized but give strong resistance to paper, ideal for recess printing. This was suggested by Nora Matassi in a conversation we held but it was just that, a conversation.
The imprint of a dandy-roll might have less effect on a very thin type of paper that has to be strong at the same time and hence [?] the difficulty in seeing any watermark!
I should try my luck on the 45c using the scanner! Maybe I can get to see some watermark
I have been working on web-pages of Argentina, a.o. for the Evitas:
http://www.galeoptix.nl/fila/arg_1952.htm
It is not ready by far - still a lot of work to be done incl. correction of mistakes
to be continued....
