Identification

Chromolithographs
common use: 1840-1930

Multi-Tonal, Smooth-Edged Stippling

Chromolithographs can be identified by the presence of smooth edged-stippling in multiple colors or tones (creating a monochromatic image). This can be seen using low magnification, such as a loupe or low-powered microscope. The number of colors or tones in each print varies, and a black outline or "key-image" may or may not be present. Notice the color images are printed with colors selected from eye by a color-separator or artist, and not by the mechanical means of color-separation used in photomechanical printing techniques (which is based on the "subtractive primary" colors cyan, magenta and yellow combining to create the appearence of a full color image).

Postcard c.1905 (click to enlarge)	8x Magnification

Planographic: Illusion of Shading, Flat Ink

Chromolithography is planographic printing process, where several color separations of one image are printed from a series of lithographic stones to create one full color image. Typically, an outline of the image is drawn in red chalk (which will be visible but not receptive to ink) and then the colors are separated by eye and transferred to the stone by a color-separater. Because the image is drawn or transferred directly onto the stone, the stone’s printing surface remains flat; the image and non-image areas are defined chemically on each color stone.

In planographic or surface printing processes, the printing plate is prepared by laying down an image in a greasy substance that will hold ink and leaving the non-image areas of the plate receptive to water, which will repel the ink. Because the method relies on chemical means to hold ink to the printing surface (as opposed to the mechanical means of etching or carving used for Intaglio and Relief printing), the planographic plate is flat. Tonal variations in the final planographic print come primarily from the amount of the plate’s surface covered with ink rather than the quantity of ink.

Image used with permission of Bamber Gascoigne from his book, How to Identify Prints.

Illusion of Shading

Because the planographic printing surface will hold ink in the image areas and repel ink in the non-image areas, the appearance of shading in chromolithographs is created by varying the amount of surface area covered (as with monochromatic lithographs) and by overlapping certain colors. For example, a print with four printed colors can appear to have more by overlapping certain colors in certain areas. Notice in the image below how the blue and yellow overlap to form green, and blue and red overlap to form purple / brown. A conventional way to create the illusion of shading in an area of a single color was to use two tones of the same color.

Illusion of shading visible, 50x magnification (click to enlarge)

Flat Ink or Level Printing Surface

Because the image (ink-holding) areas or non-image (ink-repelling) areas are defined by chemical means and not mechanical means, the surface of planographic printing plates are not altered. This means the ink of the final print is level to the surface of the paper. Notice in the image below how the ink and the paper appear to be on the same plane.

Chromolithograph Examples