WHAT IS A LITHOGRAPH?

Written and photographed by Katherine Plumer

PLEASE DO NOT REPRINT WITHOUT PERMISSION

A lithography studio.

A better view of one of the lithography printing presses.

An assortment of litho stones in the stone racks.

Most people associate the word "lithograph" with modern offset lithography (what "950 signed and numbered lithographs" generally refers to!) But the process of modern offset lithography has an ancestor called stone lithography, and that is the type of lithography that I do.

Lithography was invented in Germany in the late 1700s by Alois Senefelder as a means of replicating text. Nowadays it is an art form that is not often seen, most likely because it's not the sort of thing one can simply set up and do in one's small home studio. Modern offset lithography was said to be invented in the early 1900s, and is widely used commercially to print anything from product labels to magazines to fine art prints.

Whereas old-fashioned stone lithography produces multiple original images, modern offset lithography is used in order to produce multiple reproductions of one original art piece (so, for example, an original oil painting can be sold as "prints"). It does not use a stone (instead uses a very thin and flexible metal plate), and is a very rapid process. Rather than printing from the etched plate directly onto the paper, the image is first "offset" onto a rubber blanket, and then printed onto paper. With modern offset lithography, the artist (with VERY few exceptions!) does not physically print the image him or herself, since that is done by a professional printing company.

But, that is not what I do, and that is not the process I will present here. The goal of this book is to explain the complicated process of stone lithography in the simplest terms possible.

The word litho actually means "stone." Limestone is used for the process of lithography. The surface of the stone (which should already be totally flat, to make life easy!) has to be ground down in a process known as "graining." This involves sprinkling various sizes of carborundum (metal) grits (from rough to fine, like sandpaper) on the surface of the moistened stone, and grinding in a circular motion using either another stone placed on top, or a special stone grinder called a levigator. Only a very thin layer is taken off the top--just enough to remove any old image, and make the surface perfectly level (if it's not level it will crack under the weight of the press).

Graining the stone with a levigator.

In other printing processes, the image itself is on a different plane than the background surface. In relief printing, the image is higher than the background, which has been carved away. With engraving, the image is carved into the background surface. But with lithography, the drawn image is on the same plane as the rest of the stone. There is no carving involved.

A partially drawn crayon image on the litho stone.

The image is drawn directly onto the surface of the stone using greasy materials, usually either "litho crayons" (feel much like regular wax crayons) or a brushable material called "tusche." It is entirely possible to create an image using any type of greasy material, such as lipstick or even greasy fingers! For this reason it is crucial not to touch the surface of the stone while drawing the image! At this point the stone is considered "open," and therefore receptive to grease. It is also important to note that the print itself will be a mirror image of the actual drawing, which is something to consider if the drawing includes text or must have a particular orientation.

The completed drawing.

The stone is dusted with rosin and talc, and then buffed off with cheesecloth.

When the drawing is completed, it is dusted with rosin and talc, and then "etched." Etching is a deceptive word, because most people think that the surface of the stone must somehow be eaten away, but that is not the case. The "etch" is of a chemical nature--a variable number of drops of nitric acid (the etching strength is determined by the lightness or darkness of the drawing, and the type of materials used) in one ounce of Gum Arabic, which looks and feels much like maple syrup.

First the stone is etched with pure Gum Arabic (ok to do by hand) and then it is etched with Gum Arabic that contains nitric acid (donÕt do this by hand!). The Gum is then buffed down with cheesecloth to a very thin layer.

When a litho stone is "etched," the surface becomes stabilized. When it is printed later, the image area (where the drawing is) will attract ink and repel water, whereas the non-image area (where the stone can be seen) will repel ink and attract water. After the stone is etched, the Gum Arabic is buffed down to a very thin layer to protect the stone and keep the image from spreading. (Grease creeps! Sounds like an insult!) When the stone is protected by Gum, it is considered "closed" and not receptive to grease.

Now it's time for the second etch! First, a thin layer of ink is rolled out onto the glass ink slab using a leather roller (black ink requires a leather roller, colored inks use rubber rollers). Using mineral spirits, the original drawing is wiped away THROUGH the thin protective layer of gum that is still on the stone. The image area is then rubbed with "asphaltum," a printing base/stain (looks a bit like thinned tar) that helps the ink stick to the right place! Then, the layer of gum can be sponged off with water, exposing the raw stone surface.

Rolling out the ink with a leather roller onto a glass slab.

Washing out the drawing materials with mineral spirits.

Rubbing the stone with a printing base called asphaltum.

After washing off the layer of Gum Arabic, the image area is noticeably stained with asphaltum, and ready to be inked.

The stone is once again considered "open" and should not be touched. It MUST be kept damp. The image will now be replaced by the ink, which is done by passing the inky roller across the surface of the stone until the image is fully inked (and keeping the stone damp at the same time!)

Passing the roller over the stone deposits the ink on the surface. The stone has to be kept damp so the ink only sticks to the image area.

Once the image is fully inked, it is once again dusted with rosin and talc. This dries the ink so that it doesn't smudge or creep. If any corrections (additions of deletions) need to be made on the image, now is the time to do that. The stone is then etched again. The more times a stone is etched, the more stable the image becomes.

The stone is dusted with rosin and talc, and then buffed off with cheesecloth.

First the stone is etched with pure Gum Arabic (ok to do by hand) and then it is etched with Gum Arabic that contains nitric acid (donÕt do this by hand!). The Gum is then buffed down with cheesecloth to a very thin layer.

I like to etch an image at least six times prior to printing the edition. In subsequent etches I usually "proof up" the image (I'll explain this later) to make sure that it looks right. The etching process for subsequent etches remains the same. Repeat. Repeat. Repeat. Repeat...

Okay, now that the stone is plenty stabilized, it's time to print! Like before, the image is washed out with mineral spirits, stained with asphaltum, washed off with water, and kept damp.

Wash out the old ink.

Apply the asphaltum, and clean off the stone.

The ink is rolled out onto the glass slab, and the roller is passed over the damp stone, thereby depositing ink onto the image area. Each time the roller passes over the stone, it is (fittingly!) called a "pass."

Roll out the ink. Ink up the stone. Keep it damp!

Double duty. It's hard work printing alone!

Each time the roller is returned to the ink slab for more ink, that's called a "visit." If I were just trying to get the image fully inked so that I could etch it, I would just keep applying ink until the image was dark enough. But, when "proofing" (a necessary thing in order to PRINT!), the process is slightly different.

After three "visits" to the ink slab (before the image is fully inked), I'll "pull a proof." Proofing is done on newsprint, which is significantly cheaper than printing paper. A stone is proofed prior to printing because it is important to ink a stone slowly, otherwise under the pressure of the press the ink will settle into the pores on the stone, causing the image to darken. The paper is placed directly onto the stone, followed by a thick paper "pad," and a smooth sheet called a "tympan." The tympan is what comes into direct contact with the scraper bar on the press. The press bed is then moved into the appropriate starting point, the pressure bar is lowered (it is adjustable to the thickness of the stone) and the press bed gets rolled underneath.

The paper is placed directly onto the stone, followed by a thick paper pad, and the tympan.

The pressure bar is lowered, exerting pressure on the stone. The pressure is adjustable, depending on the thickness of the stone, and will be tightened several times during the proofing process.

The press bed is rolled beneath the pressure bar. This is what offsets the image onto the paper.

The pressure bar is then lifted, the press bed is pulled back into the normal position, the tympan and pad are removed, and the print is peeled from the stone (my favorite part!).

The pressure bar is lifted, and the press bed is pulled back into its original position.

The proof is in the...proofing! Peel it up!

The first proof will be pale. Next time I'll add more ink (another visit) and the time after that I'll increase the pressure, alternating until the image is fully inked and printing well.

A fully inked stone, ready to be editioned on good paper.

At this point, the pressure and amount of ink is simply maintained, and I can start printing on good paper (usually 100% cotton paper, though I like to experiment with others too). I generally print anywhere from ten to twenty prints in an edition (sometimes more, sometimes less), which I try to do all in one day, if possible. Once I get going, it takes about 8 minutes per print, and several hours just to get to that point! There comes a time when the image will start to darken significantly, and then it's time to call it quits. The stone can then be cleaned off, and when I recover from a whole day of printing I can grain the stone and start all over again. :-)

A series of proofs, progressing from pale to fully inked.

DonÕt forget, the print will be a mirror image of the original drawing!

So in the end, the stone itself was just a temporary location for the image. What remains is not the original drawing, nor is it a reproduction. What remains are a set of identical images, each one a HAND-PULLED LITHOGRAPHIC PRINT.

Thanks for taking the time to read this!

Written and photographed by Katherine Plumer

PLEASE DO NOT REPRINT WITHOUT PERMISSION