The Wonderful Giori Press

We have indicated the difficulty of registering colors in multicolor printing from line engraved plates. All we have stated on this matter was true and continued to be true for all United States postage stamps printed up to July 4, 1957: On that day the Post Office Department issued the very popular "Flag Stamp" on which our national standard is shown in full color. The Flag Stamp ushered in a new era of multicolored stamps for the United States. It was soon followed by other issues printed in two or more colors. The remarkable feature of these new multicolored stamps is that they are printed in all colors used simultaneously from a single printing plate. This truly revolutionary method of printing, either from intaglio or letter press plates, is the result of an invention of Gualtiero Giori after whom the printing press performing this feat is named - the Giori Press.

The Bureau of Engraving and Printing in Washington acquired one of these presses in 1957 and promptly put it to work printing the now famous "Flag Stamp." The small miracle of printing a design in multiple colors from a single plate with a single impression is achieved from a very simple principle. The plate itself is inked in as many colors as may be desired. Each color being applied to only that portion of the plate which is required to print that color. In other words the ink rollers are themselves printing plates which "print" their ink onto the plate which in turn will do the actual printing on paper. Hence, if two colors are desired two printing rolls are required, one for each color, each so designed as to pass ink to only certain portions of the printing plate. If three colors are wanted then three ink rollers are provided. Theoretically, at least, there is no limit to the number of colors that could be thus printed at a single impression.

Giori Press
stamp
Giori Press stamp
Canadian
'Seaway' stamp
Regular and inverted center. Canadian "Seaway" stamp.

The development of the Giori Press followed World War II and was first used to print postage stamps in Argentine in 1949. It is said to have also been used for some stamps of West Germany, Jugoslavia and Finland. Since its introduction at the Bureau of Engraving and Printing at Washington it has been used to produce many multicolored postage stamps; including Flag Stamp, the Champions of Liberty series and others. The Giori press has sounded the death knell to inverted centers of stamps printed in two colors. This was sharply brought to public attention in 1959 when the United States and Canada issued the now famous St. Lawrence Seaway commemorative stamp. The designs of the two stamps was as close to being identical as possible. The stamps were printed in two colors - red and blue. The Canadian "Seaway" stamp was printed in the usual way from two separate plates and shortly the world was electrified at the discovery of an inverted "center," the first major error ever to have been discovered on a Canadian postage stamp. Naturally collectors everywhere searched their collections in hope of finding one of these prizes. And for a while many searched vainly for a United States "Seaway" stamp with a similar inverted center. Such a search was hopeless for the United States "Seaway" stamps had been printed on the Giori press and on products of this press inverted centers are impossible.