http://www.filateliaargentina.com.ar/fo ... 9&start=15
about the 1956 1st Anniversary of the September Revolution of 1955 I had shown that there were 2 types of paper that can not be found in the Tello Meggia catalogue as the line of AЯ is the same in both cases - horizontal relative to the stamp design.
In reality we are dealing with a parallel watermark in combination with a horizontal direction of paper (eje de enrollamiento) or an orthogonal watermark in combination with a vertical direction of paper (eje de enrollamiento).
Parallel:
Orthogonal:
A similar case I have found just now with the 1947 Cervantes stamps, but then the line of AЯ was vertical relative to the stamp design:
Parallel:
Orthogonal:
Once more said, it is utmost important to establish the direction of paper!!