Printing processes are numerous, but all contain certain features that transform them from Print to art. Lithograms, or more commonly lithographs are unique in their art form because of the way in which they are created. Print artists may use any number of printing techniques to create one or more prints, from woodblock cuts to linoleum cuts to etched metal plate prints. However, all of those techniques are very different from the lithograph process, as you will see.

Lithograph/gram Process

People who are not artists often refer to any printed picture or tableau as a "lithograph." However, not all prints are made the same, and a true lithograph requires a block of gelatin, glycerin, ink, fine art pens, and paper that readily absorbs the ink imprinted on the gelatin. (You can also use a metal plate or piece of smooth limestone that is etched to make a print; we'll delve into that a little later.)

You're now probably wondering just how gelatin, a jiggly, gelatinous substance, can manage to produce a print with clarity. Good question, and not one that is as difficult to answer as you might expect. It starts by making a smooth slab of gelatin. There are some art supply companies that make gel slabs for you, but you can also make them at home yourself.

It requires:

• Using four packets of unflavored, colorless gelatin powder dissolved in boiling water after you have combined the glycerin and gelatin together in a bowl.
• A square or rectangular dish, preferably metal, that has straight corners and not rounded ones for the purpose of creating your slab.
• Glycerin, which helps solidify the gelatin to make it more solid and less likely to break down when you are using it to print.
• Medium-weight paper on which to draw with pen and ink. Medium-weight paper helps pick up more ink without letting it run like lightweight paper or absorb all the ink like heavyweight paper.

After you have boiled the glycerin and gelatin and skimmed off air bubbles during the heating process, pour it into your pan. It will still be somewhat liquid, but that will be resolved after you place the pan in the refrigerator to cool. After a few hours, the slab has to be carefully peeled from the pan and transferred to another flat surface.

Next, add a liberal amount of oil or glycerin to the slab. Use water-based printing inks to create your drawing or design on paper, and before the drawing is fully dry (this is the tricky part!), flip the drawing onto the saturated gel slab. Very carefully pull the drawing off the slab and immediately place another piece of paper on top to soak up the imprinted print that was slightly removed from the original by the oil or glycerin on the slab. Artists may repeat this process until the original cannot withstand any more prints and deteriorates.

The gel slab is a substitute for limestone or metal, all of which provide the required smooth surface for duplicating prints. Additionally, if you don't want a print to be reversed from your initial drawing, you can use the gel slab to imprint on a limestone or metal plate to make exact copies of your original drawing. Use of a gel slab is what is most commonly referred to as a "litho-gram", versus the other two subtypes of lithograph printing.

The Ancient Limestone or Metal Plate Process

There's an archive in Munich that houses thousands of very old lithograph stones. All of the stones are made of limestone, a heavy, durable stone that typically lasts a very long time when it is kept away from erosive elements. You could work with limestone slabs too, if you really wanted to get that far into lithography, but you might find it very difficult to store the stone slabs somewhere safe.

Later, metal plates were used instead. Metal plates can do the same thing as the stone, but you might have to re=grease and re-etch the plates until your drawing fully appears on the chosen plate material.

Here's how the process generally works for limestone or metal plates:

• You use oil or fat/grease to draw onto the plate. Keep in mind that anywhere where the oil, fat or grease is laying is an area that will remain in high relief after the next steps of the process. In other words, the high relief greased areas is your drawing, while the removed or etched areas will not show as anything other than lines or shadows.
• The stone or metal plate is then submerged in a vat of gum arabic and acid, which eats away all of the parts of the stone or metal not greased.
• The plate is then rinsed and the greased areas are wiped clean.
• The plate is covered in water such that it seeps into the etched areas. The entire plate then receives a coat of oil-based ink, which the water-filled etched areas refuse to accept or mingle. (Remember- oil and water don't mix!).
• A sheet of paper is placed over the top and pressed firmly in place, absorbing the ink and creating the expected drawing.

A gel plate will only work as long as it doesn't disintegrate and you remember to lightly clean and wipe it before putting it back in the refrigerator. The limestone will last centuries and the metal plates will keep only as long as they do not rust. As an artist, you can try all of the above to see which you prefer. As someone interested in how lithograms/graphs are made, you get an in-depth view into how much work it is to create just one of these pieces of art and why they still cost as much as they do.

How Lithographs/grams Differ from Intaglio, Woodblock, and Linoleum Cuts

Finally, let's look at how lithograph/gram printing is different from other popular artistic printmaking. Intaglio is almost a reverse printing process from the aforementioned lithograph processes. Instead of relying on the ink to sit on top of the unetched surfaces of the plate, no water is added so that the ink goes into the etched, stippled or carved cavities of the plate. This is done using a wood block, a thin piece of linoleum, or a metal plate. The water step is skipped entirely in order to produce a darker, heavier image with greater detail.

Woodblock printing also uses a wood block like intaglio, but the object is to carve away so much of the wood block that none of the cavities or recesses are printed. Instead, the remaining raised surfaces are inked and pressed onto paper. If an artist wants multiple colors of ink, he/she starts with the lightest color, working to the darkest color and carving away certain areas of the block until nothing but the areas printed with black remain. It is very limiting in that you can only make so many prints with one block until you can't make any more.

Lino prints, or linoleum prints, utilize the same concept as the woodblock process, except that you are using a sheet of linoleum instead of wood. Artists who prefer the linoleum to wood do so because it helps create very fine details. You can also be very selective with what receives the ink and what doesn't.

As you can see these other popular art printmaking processes are quite different from the lithograph/gram process. Each has its own unique results. It just depends on the artist's preference.

Written by Jacob Hawthorne for Schmidt Fine Art Gallery.