Printmaking 101

From the editor: We're into the summer term now; all but the MA students have left, but we didn't want to leave you wanting, so I have been saving up a few posts about graduate & postgraduate work, and we'll have some reports later from those students on internships and other interesting projects later this summer. So now over to William:

The Books graduate students have been embarking on a collaborative learning experience with the Visual Arts department-printmaking! With the help of printmaker and VA tutor Marcus Rees-Roberts, we've been exploring the world of intaglio prints and having a ball.

The reason we started working on this is that we run across a lot of different types of prints in the books we treat for conservation. Part of our process is documenting precisely what we find between the covers of these books, identifying things as minutely as the animal species of the leather binding, the style of the worked endbands, or even the family of print images accompanying the text. The different prints use different techniques and materials to create the images, affecting the treatments we choose in conserving them. Learning how to make these prints helps us understand these differences and aid in identifying them.

Marcus decided to start us out with etchings, a popular technique for much of modern book publication. Etchings are a type of intaglio printing process, meaning that an image is made in a surface (in this case, a metal plate) and when applied the ink sits in that image, as opposed to a relief print where the ink sits on the surface of the image. With etching, the image is made in the metal plate using acid.

To begin with, we obtained some copper plates with the kind assistance of the Clocks and Metals departments-we cut plates of about A5 size from a large sheet of copper and then filed the edges smooth and slightly rounded the corners so nothing would catch during printing.

Since we only want a certain part of the copper plate to be removed by the acid, those areas that must remain un-etched are covered in what's called a resist, a wax-based material that is applied to the copper to form a ground, into which the image is drawn. We heated the plates slightly and applied the resist, then used a roller to get an even coating across the surface of the plate. It came out with only a slightly darker appearance due to the resist, so we smoked the resist to make more contrast between the ground and the drawing, which would make seeing our progress easier. To smoke the resist we lit a thick rope and held the plates overhead, allowing the smoke to deposit soot on the resist and darken it.

Once that was done, we began drawing our desired images into the ground. We used a variety of different tools-nails, needles, and other thin, sharp instruments-to scratch away the resist. That was all we needed to do, unlike other intaglio processes where the printer uses the tools to remove metal or scratch into the surface. The acid does that in an etching.

Finished with our images, it was time to bite the plates. Biting means to allow the plates to sit in an acid bath and let the acid eat away or bite the exposed copper, leaving the metal covered in the resist alone. The acid we used is ferric chloride, and provides a cleaner bite than other, more traditional acids. Once the plates were bitten, we removed the rest of the resist with white spirits prior to preparing the plates for printing.

Last but not least-printing! Intaglio printing requires a lot of pressure, since the ink is held in the grooves created by the etching of the plates. The paper used must be strong enough and flexible enough when wet to be pushed up into these grooves and pick up the ink. Heavy blankets are placed on either side of the paper and printing plate as it goes through the press, protecting the press and allowing this intense pressure.

Since the image is made up of the etched lines, we only wanted the ink to rest inside the etched areas. The thick printer's ink gets applied with a tool like a small squeegee, using it a bit like a blade to push the ink into the grooves and fill them up. Once the ink is sufficiently applied, the excess is wiped from the surface with scrim, a cheesecloth-like material, in a twisting motion that ends by pulling up from the plate, so that the ink in the image is pushed down while the leftover is pulled up. After the plates were wiped to our satisfaction, the edges were cleaned with paper towels and then lightly wiped one last time with thin tissue.

As I said earlier, the paper is wet when printing to allow the paper to be pushed up into the etched lines of the image and pick up the ink. We soaked the paper while we inked our plates prior to printing. Once we were ready to print and the paper had soaked long enough, we pulled the sheets out and removed the excess moisture by placing the paper between blotters and applying pressure in sweeping motions with our hands. When the paper had a matte appearance instead of being shiny with water, we knew it was just wet enough to print.

On the bed of the press we laid a registration paper with the edges of the printing paper and the edges of the plate marked to be able to get them lined up just right. A piece of tissue went on top of this, and the plate dropped carefully onto the tissue; this allowed us to carefully and easily position the plate on the registration lines by pulling on the tissue. The damp paper went on top of this, followed by a sheet of newsprint, and then the felt blankets were laid on top of this.

Then the fun part-cranking the handle of the printing press to pass the entire bundle underneath the pressure of the turning wheel to create the print. The press needs to exert enough pressure so that when the wheel rolls over the plate, slightly more resistance is felt in turning the handle.

Once out from under the wheel, the blankets are lifted up, the newsprint pulled away, and the print lifted from the plate. Ta-da! A printed etching. We laid them in drying racks where they will sit for three to four days, before being re-moistened and laid between blotters under weight to get them perfectly flat.

Learning how the process of etching images and printing from them has definitely increased my appreciation for the art of printmaking and its importance in both fine art and the application in book printing! It's demanding work but satisfying and eye-opening as well.