Bernardino Rivadavia essays for postal envelopes were prepared in 1863 in what could have been the first postal stationery issue of Argentina, For still unknown reasons the Rivadavia envelope was issued only in 1876, or some thirteen years after the essays were prepared.

The development of Argentine postal stationery issues is aptly illustrated with archival materials from the Compañia Sudamericana de Billetes de Banco de Buenos Aires. Many of the essays, die proofs, unissued values, color, sizes, and errors are acknowledged to be ONLY KNOWN or RARE. Usage amply covers the significant issues, in several instances to destinations deemed unique for Argentine mail for the period covered by the exhibit. The five postal stationery categories and its specifics are as follows:

This section is highlighted, among others, with the 1863 Rivadavia unadopted essays; the 1876 Rivadavia First Issue with three of the less than ten known used examples; the 1890 Provisional Issue with the only unrecorded and known surcharge error usage; and the only known foreign usage of the 1899-1901 Redesigned Liberty Head Issue.

Introduced with the National Bank Note specimens of the 1878 Esteban M. de Luca First Issue. The succeeding issues also well represented with design essays, proofs and printing errors. This is complemented with the varied destinations on used examples of the important postal card issues. 

The Reply Cards section is highlighted with two rare examples of unsevered cards used both ways and numerous used back Reply Sections from countries such as Egypt, France, Germany, Brazil, Belgium, Sweden and Iceland.

Illustrating the three types of Letter Envelopes, namely, New Year Greeting Envelopes, Commemorative Envelopes and "Memorandum Postal" or envelopes for common use. This section, in 16 pages, illustrate proofs, errors and usage and is highlighted with the extremely rare 1903 "Memorandum Postal" 15c Unlisted Value.

Covers six important issues starting with the 1888 Miguel Suarez German First Issue, with the four values in different sizes. Four items in this section are of significant importance to Argentine postal stationery issues. They are, the 1888 Celman 4c card with pasted view on the inside; the 1889 Advertising Cards authorized by the Post; the 1892-1896 Rivadavia design essays in three colors; and the 1899 Liberty Head 4c and 5c unadopted design and color proofs.

Highlighted with the proofs of the 1878 -1880 First Issue. Some of the succeeding locally printed issues illustrate essays, proofs and unadopted colors and sizes. The selection of entire used copies are deemed to be scarce to very scarce.