30/20 Twill-binding :
Direction of paper: parallel to the line of RA
Asymmetrical mesh
Mesh - virtual shape: little lozenges
Sun: round
Diameter: 10 mm
Horizontal distance between the hearts of the sun: 17.5 mm
Vertical distance between 2 identical lines of RA: 30 mm
Letters of RA: see picture above!
Used for the first time in 1943/1944
to be continued ...