In the rush to produce posters, building wraps, brochures, and print books for either promotional or educational purposes, we may forget that one of the main uses for custom printing for centuries has been to reproduce copies of fine art.
Some Techniques and Technologies
For the most part, custom printing techniques for fine art prints fall into three complementary categories: relief, intaglio, and planographic.
Relief Printing
Relief printing includes such techniques as linoleum block or wood block printing, in which a raised area of the printing plate (in this case a block of linoleum or wood) will transfer ink to a substrate (such as paper).
The artist uses gouges and other tools to remove all portions of the linoleum or wood block’s surface that are not the actual artistic rendering. Then he or she uses an ink roller to distribute ink across the linoleum or wood block’s surface. The next step is to lay the paper substrate on the block and apply pressure (by hand or with a press). All inked areas of the block will then transfer the image to the substrate.
Intaglio Printing
Intaglio is the term for the second technique, in which the custom printing surface is below the flat surface of the plate. This category includes the process of engraving, which is used for fine art prints and for such commercial items as engraved invitations.
In the engraving process, the artist uses a sharp instrument called a burin to dig grooves in the printing plate (which is made of copper or another metal). Areas that will print as part of the fine art design will be recessed into the metal, while all non-printing areas will be untouched. This is the opposite of the relief process described above.
Once the artist has completed the design on the plate, he or she dabs thick ink across its surface, being careful to get ink into all the grooves that comprise the artwork. Then, all ink on the surface of the printing plate is wiped off, leaving ink only in the recessed grooves. The artist mounts the plate on the press, inserts a piece of moistened paper into the press, and then uses the press to transfer the inked image from the plate to the paper. The intense pressure forces the fibers of the printing paper into the inked grooves cut into the custom printing plate with the burin and transfers the image. At this point, the plate can be reinked and another impression can be made on a new sheet of paper.
The intaglio process also includes such techniques as etching, in which a waxy resin resistant to the effects of acid is applied to the surface of the coper or zinc plate. The artist uses an etching needle to cut through portions of the waxy resin to create the design. When the plate is then immersed in an acid bath, the acid eats into the plate in all areas not covered with the acid resist substance. Once the plate has been etched, the artist can apply ink, wipe off all ink on the surface (but not in the grooves cut by the acid), and then proceed with the custom printing process as with an engraving.
Etching (as opposed to engraving, which involves direct cutting into the plate with a tool rather than an acid bath) includes such techniques as aquatint and mezzotint, while the more direct process of scraping into the plate includes such techniques as drypoint and wood engraving.
Planographic Printing
The planographic process employs a completely flat plate. Image areas are not raised (as in relief printing) or recessed (as in intaglio printing). They are on the same level as non-image areas. This is the same process used for offset lithography.
Planographic plates are based on the incompatibility of oil and water. Oil repels water; water repels oil. Treating the image areas of a custom printing plate in such a way that they attract the oily ink while water covers all non-printing areas of the plate allows the plate to deposit the ink precisely.
In offset lithography, the plate first prints the image onto a fabric or rubber blanket and from there onto the paper substrate.
In more traditional lithography, in which the artist draws the image on a limestone plate with a special greasy crayon, the greasy markings attract the printing ink. At the same time, water applied to the surface of the plate is repelled by the greasy image area. When the artist lays moist paper onto the printing plate and runs it through the press, the intense pressure transfers the inked image to the paper substrate.
Silkscreen Printing
The final technique fits into none of the prior three categories. In silkscreen printing, the artist creates an image on a silk (or metal) screen that has been stretched over a wood or metal frame. Areas that will not print are blocked out (using a resist substance like shellac), while image areas are left open. The artist deposits ink at one end of the screen frame, lays the frame down over the paper substrate, and using a rubber squeegie, drags the ink across the screen. This forces the ink through the portions of the screen that have not been blocked out with shellac and onto the paper substrate.
For each successive color, the artist cleans the screen, uses shellac to cover all areas that will not print, and repeats the inking and squeegeeing process.
While this description implies that the artist has created the image by hand on the successive screens, he or she can also use photomechanical methods to create halftones that can be printed in the same way.
The Take-Away
Printing is an art and a craft. The books, posters, and business cards you design are printed with many of the same, or similar, techniques as have been used through the centuries to produce fine art prints.
This entry was posted
on Tuesday, July 22nd, 2014 at 11:51 am and is filed under Large-Format Printing.
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