From 1938 onwards Courvoisier S.A. used the reel-fed method for photogravure having usually 4 counter sheet pro cylinder.
Stamp size with perforation 11 3/4 and 14/17 teeth hor. / vert. almost without exception had direction of printing D [ink flowing downwards] for the portrait size and R [ink flowing towards the right] for the landscape size. 4 counter sheets of 10x10 on the cylinder.
Stamp size with perforation 11 3/4 and 15/24 teeth hor. / vert. almost without exception had direction of printing L [ink flowing to the left] or R [ink flowing towards the right] depending on the position of the counter sheet for the landscape
OR
U [ink flowing upwards] and D [ink flowing downwards] depending on the position of the counter sheet for the portrait size in the period of 1938-1965.