Viscosity printing

Viscosity printing is a multi-color printmaking technique that incorporates principles of relief printing and intaglio printing. It was pioneered by Stanley William Hayter.

The process uses the principle of viscosity to print multiple colors of ink from a single plate, rather than relying upon multiple plates for color separation. It is a fine art printmaking technique, making original prints in limited editions, as it is slow and allows too much variation between proofs to make large editions feasible. Color viscosity printing is among the latest developments in intaglio printmaking. Stanley William Hayter developed it during the late 1960s in Paris.

There are a number of different types of original print methods to be aware of. Intaglio prints: for example a dollar bill—bills and most stamps are engraved in metal plates and are printed after a viscous ink (about the consistency of oil paint) is forced into grooves, scratches, etched lines or indentations. The polished surface is then wiped clean using newsprint and tarlatan, leaving ink only below plate level. The plate is then covered with a dampened paper and felt blankets. It is run through the press where great pressure (approximately 8 tons to the square inch) pushes the dampened paper down into the engraved or etched grooves to pick up ink. In other words, in intaglio we see printed what is below the surface of the plate and the ink is now embossed on the paper. Among the greatest masters of engraving and etching are Albrecht Dürer, Hans Holbein the Younger, Rembrandt, Goya, and Picasso.

Three to four colors of ink are mixed, each of a different viscosity. This viscosity is adjusted by the addition of uncooked linseed oil.

Metal plates, usually copper or zinc, are used, as in the intaglio processes. The artist produces images on the plate by etching lines or textures. The plate is then inked in several stages. The first ink would be fairly dense—of a relatively high viscosity. The application of the high-viscosity ink is carried out as in any intaglio process: by forcing it into the recesses of the plate and then wiping off the plate's surface with a tarlatan.

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