REPRODUCTION OF ILLUSTRATIONS 



use of five separate stones unless, as often happens, 

 colors can be produced by superimposing them or by 

 combining more than one color on a single stone. The 

 artist will then select a color, red, let us say, noting 

 from the keystone every patch of red as outlined there. 

 In exactly the same positions on another stone the out- 

 lines for the reds are made, of corresponding shapes, 

 omitting all other parts of the picture. On a second 

 stone he will treat the outline of the blues in the same 

 manner, on a third stone the yellows, and so on until 

 each color to be used is represented on the stone in a 

 position so that if the colored inks are applied and a 

 piece of paper in an exact relative position to each stone 

 is successively pressed upon each of these stones, a pic- 

 ture in five colors, practically duplicating the original, 

 will be produced. 



Of course if each of these patches of color on a stone 

 were simply outlined, leaving a perfectly flat surface for 

 printing, with the remaining surface of the stone cut 

 away by the acid, the result would be a perfectly flat 

 mass of color for each patch so treated. As shading is 

 usually desired, however, this is produced with chalk 

 or pen as described a moment ago, dark patches of 

 color being indicated by heavier marks and the lighter 

 ones by correspondingly lighter marks. 



In recent years aluminum has been used extensively 

 to take the place of lithographic stone. On this metal 

 the inks can be worked well, and its lightness and 

 relatively small bulk have brought it into general favor. 

 In the same space occupied by a single lithographic 

 stone a great number of aluminum impressions can be 



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