Intaglio (from the Italian intagliare, to incise, engrave) could be argued to be the “best” printing method. Because it prints from ink held in grooves in a metal plate, the amount of ink applied to any point can vary in infinite gradations. Both relief printing and planographic printing deliver the same amount of ink onto every spot whereas intaglio can stack it up in the shadow areas. This is of course irrelevant in the printing of text, but can make for dramatic effects in the reproduction of pictures.

Before the invention of photography there were two ways to get to a plate ready for intaglio printing: engraving and etching. In engraving the lines are cut into a sheet of metal using a steel burin. In an etching, the metal plate is covered by a layer of waxy, acid-resistant “ground” and then lines are drawn into that layer exposing the metal below. Dip the plate into an acid bath or pour acid over it and the exposed lines will be etched into the underlaying metal leaving the areas protected by the ground or resist unaffected. The wider the line the deeper the cut. The deeper the cut the more ink, potentially, available to be pressed onto the paper.

Engraving was for a long time the only route we knew for getting to an intaglio printing plate. Starting with wood blocks, engraving moved onto metal (copper mostly) and was sufficiently demanding that a whole craft grew up around it. You’ll often see little attribution notes: “Joe Bloggs pinxit, Fred Spoons sculpt.” indicating that Fred engraved a copy of Joe’s painting. The skill and control needed to engrave a steady line was beyond most painters and became a specialized craft in its own right. However when etching was developed in 16th century Augsburg, painters and other graphic artists were quickly able to see that while control of a burin in a sheet of metal might be beyond them, using a point to scrape a design into a field of wax was something they could manage with freedom.

Tell-tale differences between engraving and etching are that with etching the lines tend to have blunt ends — the sharp ends of an engraved line are softened by the passage of the tool through the resist before reaching the metal surface. The lines in an etching may also tend to have slightly blotchy edges as acid creeps in below the cut edge of the resist. But it’s important to realize that a plate which started out as an etching might be touched up and “corrected” by engraving too, so that most of the prints we see are combinations of both techniques.

from Benson: The Printed Picture

In this picture of an etching with some engraved afterwork you can see evidence that the ruled background shading, which we might expect to have been done after etching with an engraving burin and a straight-edge, was in fact done with an etching burin through the resist layer. The top diagonal line is the give-away: that little turn back at the end of the line is just not something you could do with an engraving burin, whereas when you raised your hand you might easily remove enough wax to leave that little flick of a tail. Note also the blunt ends of the lines.

Sub-categories of etching include aquatint and mezzotint, which I will cover in separate posts. Drypoint is a sort of halfway house between relief and intaglio printing. It is done as after-work on an already etched plate. Using a needle the artist will raise a little burr of metal which will catch ink and print a different effect. Because these little burrs are delicate, drypoint cannot make long runs. It’s easy to overlook the difficulty of making prints back in the days before photography and digital methods. Everything had to be done in a resistant medium and then printed on a hand press. Some of the effects achieved by combining all methods know to the industry resulted in utterly amazing effects. Indeed when we look at some of the printed images, often representing utterly banal subject matter, we have to wonder at the huge amount of skill and effort expended for such an apparently trivial picture. Richard Benson’s The Printed Picture includes some mind-blowing examples.

There’s an etching exhibition at the Metropolitan Museum of Art in New York City now; The Renaissance of Etching. It closes January 20th. They have a link to this explanatory page about etching.

Here’s an etched iron block from the show. You can see blotches of rust on its face, inevitable when ink is constantly being spread onto it and then dampened paper pressed against it. It’s the printing block for “Venus, Mercury and Cupid” by Hans Burgkmair and dates from c.1520, and comes from the British Museum.

That a printing block might be made from iron or steel becomes less surprising when one recognizes that the print technique of etching evolved from the decoration of armor. Augsburg had long been a center of armor production, and it was there that the art of printing from etchings evolved.

Rembrandt has been referred to as the father of etching, though the process was of course invented well before his time. Here’s a YouTube video about the subject, which also shows a couple of process sequences demonstrating how etching is done.

If you don’t see a video here, please click on the title of this post in order to view it in your browser.