Charter embraced by the III° Plastic Arts International Congress, Vienna September 1960:

It is exclusive right of the artist to fix the number of copies of each artwork executed in the different techniques: Aquafortis, Lithography, etc..

Each print is to be regarded as original, and has to be signed by the artist himself. A print should include the total number of the print run together with the progressive number of each print.
The artist can note on the print if it was printed by himself.

When the printing is finished It is suggested to etch the stone, wood or the metal matrix, to signify that the print run has taken place.

The principles enunciated above are applied only to original prints. Works that doesn’t satisfy these conditions must be considered as "reproductions".