To lay on the color, proceed as follows:—
First the black is rubbed-in, as prescribed in the article on the intaglio style. In the very deep parts the stone will get very black. In the parts last drawn, that are level with the surface, it will be only gray, if the color permits ready wiping, which can be facilitated by the use of gum and a woolen rag. Then the tone remaining on the level parts drawn with the chemical ink will be so pale that it will not affect the blue color. Now wipe a rag dipped in blue color gently to and fro till everything that is to be blue has taken the color well. Then take the dauber which has been filled with red color, and pat the stone, which should be dry by that time. Then the parts of the design in high relief will take the red color, and thus an impression can be made with the three colors at once. Each inking-in must be done the same way.
III
USE OF THE STONE FOR COTTON-PRINTING THROUGH WIPING. A UNIQUE PRINTING PROCESS
Etched copper plates have been used for some considerable time for cotton-printing, and as the ordinary oil colors were not suitable for this, while the suitable colors were too fluid, so that they were always wiped out of the engravings, another method was devised. The plate was covered with color and then a kind of straight edge was scraped across it, which removed all color from the surface, leaving it only in the depressions.
This same sort of wiping is applicable to stone, and it is necessary merely to see that the stone is very even and highly polished. The color must be one that permits itself to be wiped off clean, and the wiper must be very uniform and sharp.
Starch-paste or gum with some caustic material is easily scraped off.
IV
COLOR PRINT WITH WIPING
This process is also useful for printing papers such as cotton papers, tapestry, etc. Almost all intaglio designs permit good printing in this way, if a handsome color is used.
Fresh cheese, or drops of congealed milk, mixed with soap, potash, linseed oil varnish, and the desired tint, make an excellent composition, with which all intaglio designs, even aquatints, can be printed handsomely if the plate is very smooth.