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Exhibits from Towson University's Special Collections and University Archives

Metal Plates

Woodcarving is an easy way to create print blocks, but not the most durable. Over many printings the pressure of the press grinds down the wood surface and ruins the crisp lines of the image. So while covers for specific issues of Towson University newspapers used wood blocks, images that would be printed in very large volumes, or across many publications, would be created from zinc or aluminum metal.

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Alma Mater Class Song of 1940 relief block

Making Metal Plates

To make metal printing plates, also called offset plates, an artist first draws the image they want to reproduce and makes a negative of that image. Next, a sheet of metal is coated with a thin layer of light-sensitive material. The negative image is then placed on top, and both are exposed to intense light. The light hardens the exposed parts of the metal, resulting in some areas of the plate that are harder than others. These areas will form the image.

When the metal has hardened, the negative is removed and the light-sensitive material is washed off the unexposed areas of the plate. This unexposed metal is then etched away using an acid solution. The light-hardened parts of the surface remain raised above the etched-away space, resulting in the finished printing plate.

The metal sheet is then mounted on a wooden block to make the printing process easier. When ink is applied to the completed block, the raised areas will create a clear, crisp copy of the original design.

The State Teachers College at Towson used this method to create many plates depicting school buildings - especially the iconic Stephen’s Hall clock tower - as well as illustrations, comics, campus maps, and sheet music, like the plate pictured above.