Printmaking

When we attend to an exhibition either in a museum or an art gallery, we can see, besides the traditional art techniques such as oil painting, gouache or watercolour painting, another form of pictorical expression known as fine art printmaking.

Fine art printmaking is a generic term that embraces a different set of techniques developed over centuries, from the traditional woodcuts to the most modern ones such as offset printing. All of them are born of the same idea, transferring the image created by the artist on a form, which may well be a plate made of metal, wood or stone or a roller, to a support, usually paper or fabric.

A fine art print is considered as such, if it meets certain requirements; it must be the artist's creation, who must work directly on the plate, the edition should be limited and the plates have to be destroyed at the end of the process, since this ensures the uniqueness of each of the copies. It is also important that the works are numbered and signed by the artist or include any mark or stamp the author's own.

The foil or metal surface is coated with a varnish very thin but resistant to acid, on which the artist draws with steel spikes, leaving with his traces the metal bared. Then the plate is immersed in a nitric acid solution, which records the lines left by the bare metal. Finally the plate is washed with water and the varnish is removed with benzine so that it is ready for printing.

The metal surface is covered with powdered resin that is adhered to it by heat. Then, as in the etching, is engraved in acid, which attacks the copper plate in places not protected by the resin. The result will be a dotted drawing on black or brown background obtained through chinese ink, sepia or bistro.

Using a burin, the drawing is recorded on a square or rectangular block of boxwood.

The drawing is engraved directly on the metal plate with steel spikes and burins as those used for engraving wood, without the intervention of any acid.

Metal engraving obtained by a process similar to etching, but using a soft mordant bath. After the metal plate is coated with a thin layer of tallow, one or more sheets of paper are placed upon it and the drawing is done in pencil on them. The metal is exposed in the drawn parts, that are attacked by mordant into a fairly long bath. The resulting engraving gives the appearance of a pencil drawing. It achieves good results when combined with aquatint.

The physicochemical process of the lithograph print is based on the antagonism between water and fats. The surface that has traditionally been used is limestone although currently it is used a flexible sheet of zinc or aluminum that must be treated to get a granular surface as the stones.

These plates are prepared by introducing them in acid and scraping with sand or pumice stone to acquire the porousity of the limestone. Following, the inverted image is drawn using oil and the surface is covered with an aqueous preparation of nitric acid and arabic gum to set the lithographic image and the virgin areas are cleaned. Next, the plate is soaked with water, that will penetrate only the clean areas and will be repelled by the grease in the lithographic image. The printing ink is applied with a roller on the wet plate so that only the grease design will accept the ink.

Before printing, the stone is dried and errors are corrected with a blade or a pumice stone, the plate re-washed and more ink is re-applied. Finally the plate is placed in the press and the image is transmitted to paper.

It is a lithographic printing technique where the image is first transferred from the metal plate to a rubber roller and then from it to the paper.

For silkscreen printing it is used a screen or sieve, consisting of a silk fabric, synthetic or metal fiber, stretched on a frame that nowadays is metalic and formerly was made of wood. This screen should be prepared through a manual procedure, which may consist on placing trimmed templates on it, applying filler liquid or using photomechanical shutter systems. The purpose of any of these methods is that the mesh becomes clogged in the areas that are not being printed and open in the areas that correspond with the silkscreen image.

Once the screen is prepared, the medium that has to recieve the impression is placed under it, and over it the ink pressed with a squeegee. This operation must be done manually or mechanically as many times as mediums to be printed and as many colors are needed, previously drying each of the preceding colors.

The origin of the silkscreen is attributed to both the Chinese and Egyptians. Their deployment in Europe is recent, firstly introduced in Britain around 1890, and later in France, especially in the Lyon region, where it was exclusively used for textile printing. It was the early twentieth century when the first graphic applications take place, and in the decade of the sixties the pop artists claim its use to represent their vision of popular culture.