10c Rivadavia Brown First Clay Papers

I have spent some time grouping this value, that may well be the most difficult-to-type value of this series. Here I show the first clay paper issue on reddish brown, the CL1A, from 1939; and the second clay paper on dark/blackish brown, the CL1B, beginning use in approximately 1941.

I do not coincide with the information I came across in an article by the proposer of this series, Tenorio, who mentions that the first printing was on offset and was placed in circulation March 16, 1939. Tenorio mentions that the first clay typographed issue was placed in circulation November 4, 1939. Tenorio mentions that the offset issue is rare, and I do not find it. This is what I find:

I find the CL1A cancelled May 1939.







I find it as an official issue overprinted "Servicio Oficial"



This stamp is less common than most other 10c Rivadavia Browns, but this is relative rarity since these stamps saw heavy use. I only find one cover with this stamp, dated August 20, 1939:





The differences between the CL1A and CL1B clay papers is minimal. The sun for the CL1A is slightly larger than the sun for the Cl1B; the CL1A is flatter, and the CL1B is thin and shows the watermark in relief.

The CL1Bs are slightly darker and show more plate wear. By 1941 the plate shows dots of wear that show up throughout the design as a grid.







I find it as an official issue overprinted "Servicio Oficial"



I find it on over, but it is not common in this format: