Electro Painting.

Scientific American 47, 11.8.1849

The principle of this process consists in the production of an electrotype copper cast of the drawing itself. The drawing is to be made on a perfectly smooth unburnished metal plate, the size of the drawing; German silver is well adapted to the purpose. This plate is not injured by the process, and can be used repeatedly. The pigment employed is thus formed; Two parts of tallow and one of wax are to be well mixed together in a melted state, and blackened wit the finest lamp-black; a small portion of this mass must then be rubbed down with turpentine; but the aid of a palette-knife, to the xonsistency of oil-paint. With this paint, a drawing is to be made with an ordinary paint-brush on the German silver plate. The paint flows readily from the brush, and forms raised touches on the smooth plate; the touches intended to print the darkest being raised the highest.

Various methods of working will suggest themselves to artists. A leather pad is very useful for producing broad flat tints; and good effects may also be obtained by using a leather stump. Even the palette knife may occasionally lend its aid. The artists can judge of the effect of the print from the color of the drawing; the tins of the one corresponding, very closely with the tints of the other. The highest lights are obtained either by leaving the German silver plate bare or by wiping out portions of this paint.

When the drawing is finished the finest French bronze powder (the same as that used for printing gold letters) must be freely dusted over its surface with a large and soft camel's hair brush, care being afterwards taken to brush away all the bronze which does not adhere to the drawing. A drawing with a metallic surface is thus obtained; on which an electrotype copper plate, a perfect cast of the original drawing and of sufficient thickness to bear the pressure of printing, may be readily deposited.

The electrotype plate, when taken off the drawing, must be carefully washed with turpentine to remove any bronze or paint which ay adhere to it, the edges must be cut square, and the back of the plate filed smooth - and it is then ready for the printer.