The graphic work is a direct result of the artist’s work on a support, either made of wood (xylography), metal (engraving), stone (lithography) or textile (serigraphy). Once the sheet is prepared, it is stamped by using handcrafted methods with the help of a rolling press. 
This press consists of a steel slide that will go through two heavy steel cylinders. Under extremely high pressure and with the help of felt layers in between the cylinders and the slide, the moisten paper is put in contact with the ink of the template sheet.
The traction power needed to accomplish this task can be either direct or aided by a gear assembly. In many cases a motor is included to facilitate the work.

In the original work, the edition is limited and the artist signs and numbers each of the copies. Therefore, the price will be variable depending on the artist, the number of copies available and the technique that he used. For classic engraving, the metal sheets are ancient even if the edition is modern. The engraver and artist signatures, as well as the editor’s reference, are included in the sheet. The difference between the original piece and a reproduction will be that in the latter a photo-mechanic stamp is performed without a direct intervention of the artist.

1_ Xylography (relief engraving)

The matrix, usually made of wood, is carved using different size of gouges and burins. “Xylo” comes from the Greek “xilon”, that means wood, so this technique could be seen as wood engraving.

2_Engraving (Photogravure)

On a metal sheet, usually made of copper or zinc, the engraver carves the traces. This method can be subdivided on different techniques:

2.1_Etching: as a first step, the sheet is covered with varnish and on it, the artist designs with a burin the composition. Then, the sheet is introduced in etching (nitric acid diluted in water), capable of penetrating in the areas of the sheet that are not protected. Afterwards, the sheet is cleaned and the ink is introduced in the traces. Finally, the printing on the paper is performed.

2.2_Aquatint: it is a variety of etching that uses resin powder. As this product shrinks with heat, it allows the acid to penetrate. When the stamping is carried out an excessive pressure must not be applied to ensure the characteristic aquarelle resemblance is preserved.

2.3_Burin engraving: in contrast to the previous techniques, here the carving is directly carried out on the metal sheet.

2.4_Dry point engraving: the carving with a sharper tool than a burin, but with no cutting edge. With this technique, the metal chips are not discarded. They are kept on the sides of the traces, creating a velvet-like sensation.

2.5_Soft carving: it was a common used technique in the 18th and 19th centuries and it is the result of combining the etching (used for the outlines) and the burin (used for the shadows, to create volume).

3_ Lithography

The supports used are limestones, porous, with capacity to absorb both water and grease. With a grease-based pencil or ink, the artist designs a drawing on the stone in such way that the ink or pencil powder that penetrates in the pores of the stone matches with the design. Then, the drawing is fixed with nitric acid and acacia gum.
To stamp the design, it is enough to moisten the stone and paint it with grease ink, as this will only penetrate in the pores that are part of the drawing.

4_ Serigraphy

The artist combines covered or blank areas with other open or image areas, on a silk, synthetic or metallic screen. For the stamping, liquid ink is poured on the screen and this will only be able to go through it in the areas of the design. Therefore, in the serigraphy, the printing is not carried out by pressing, but by filtration.