VINTAGE POSTERS DENVER VINATGE POSTERS DENVER VINATGE POSTERS DENVER

This is how color posters were printed prior to about 1935.

The process of stone lithography, although simple in concept, was quite laborious in reality. The stones used were large, poster-sized slabs of limestone. From a line sketch, the draftsman drew the image on the stone with a fatty substance. Next the stone was washed down with an acid solution. Then colored ink was applied by roller to the stone, adhering to only the greasy surfaces. The final step was to firmly apply a sheet of paper to the stone surface to obtain the reproduction of the drawing.

If this process seems incredible, now imagine it being repeated for each color in the poster. If the poster had fifteen colors, then fifteen stones were used, one per color. For each poster there was one lithographic run per color.

While you are looking at the posters, note the small x's on the top and bottom. These were used by the lithographers to line up each color run.

This is the process to create a single copy of a poster. Typically 1,500 to 5, 000 copies of a poster were printed. How many posters survive today is not known.