Today, March 4th – back in 1880 – was a pretty big day in the publishing world; it was the day half-tone engraving was first used, appearing in New York’s “Daily Graphic.”

Half-tone engraving – otherwise known as half-tone cuts – are created from photographs. Originally, a photo was taken through a pane of glass on which was painted lines or dots – anywhere from 80 to 300 per square inch. This was referred to as a coarse half-tone screen. A plate of copper or zinc was coated with the solution used in making photo paper; then the photograph was placed upon its surface. The plate was then placed in a device that resembled a cradle. Acid was poured in so that the surface of the plate would be covered when the device was rocked. The acid, you see, would eat between the lines of the photograph, etching a shallow reflection into the plate. This method was replaced by lasers; and of course now it may all be accomplished digitally.

The end product, from afar, may look something like this …

Upon closer inspection, however, you’ll notice the dots that make up the picture.

So what does this have to do with books, you ask? Not a whole lot actually. Coarse half-tones are inexpensive; therefore, they are typically used in newspaper and magazine production. They can be printed on book paper, though it rarely occurs. Still, unlike wood, half-tone engraving still exists, in one form or another.

It can also be built upon for color-printing processes. But that, my friends, is another post, for another time …