The axis of coiling - literal translation of "eje de enrollamiento" is parallel to the direction of paper in most cases. Take soaked off Evita lower face value stamps and their coling axis will usually be parallel to the long aside of the stamp, i.e. vertical. Not surprisingly as all these stamps had been printed on a sheet-fed press with piles of flat sheets. Sheets that had had the time to "lay flat" !
The complication comes with stamps that had been reel-fed printed like the stamps printed in typography on the German Goebel press. Take a 20c Torito or a 20c JSM and let them soak and get dry again. The result is different! The paper of these stamps had been coiled all the time before the print had been made.
