As to the 1963 series the most frequently used paper was from Zárate both uncoated and coated - some however had imported paper from Wiggins Teape or L. Kupferschmidt......
The 11p on uncoated paper from Zárate; orthogonal watermark, symmetrical paper mesh and vertical direction of paper!
![Imagen](http://www.galeoptix.nl/fila/argentina/thumbs/arg_1963_11p_aereo_mi_10.jpg)
![Imagen](http://www.galeoptix.nl/fila/argentina/thumbs/arg_1963_11p_aereo_mi_012.jpg)
![Imagen](http://www.galeoptix.nl/fila/argentina/thumbs/arg_1963_11p_aereo_mi_14.jpg)
The grooves are predominantly present at the back of the stamps which means - in the context of Zárate that the watermark should read RA instead of AЯ
to be continued ...