|
 |
THE COMPLETE
GUIDE TO
LIMITED EDITION ART PRINTS
How to Identify, Invest & Care for Your Collection
by: Jay Brown |
|
|
CHAPTER 3
- THE NEW GENERATION - FINE ART OFFSET LITHOGRAPHY |
Fine Art of Offset Lithography Defined
Offset Lithography is the printing process that creates
the highest quality reproductions possible from an original painting. In offset
lithography (also known as photo-offset lithography, photo-lithography,
planography, offset, photo-offset and lithography), a large rubber roller, or
“blanket,” lifts the ink from a printing plate and transfers, or “offsets,” it
to paper using gentle pressure. The final result of this procedure is called an
offset lithograph.
Offset lithography is based on the principle that water
and grease (or oil, or in this case, printer’s ink) do not readily mix. The
offset lithographic printing press uses plates whose image area is receptive to
grease (ink) and whose non-image area is receptive to water. Photographic and
chemical processes create the water and ink-receptive areas on four separate
plates — one for each standard ink color.
Standard printer’s ink colors are also known as
“process colors;” they are cyan (blue), yellow, magenta and black. These four
colors are broken down into networks of dots, which create what the eye
perceives as hundreds of thousands of different colors.
Most “four-color” or “full-color” printed pieces, which
include everything from books and magazines to greeting cards, brochures,
product packaging, and even cereal boxes — are created using this four-color
offset lithographic process.
When artists want the highest-quality photo
reproduction of their original art, they usually choose the process of offset
lithography. While similar to the four-color process used to create magazines
and brochures, fine art offset lithographs exhibit one major difference — the
quality. In fine art offset lithography, highly skilled technicians can use more
than 25 colors of ink (in addition to the four basic process colors) to create a
print that is a reproduction of the highest possible quality.
You may wonder why, when the four process colors can
reproduce hundreds of thousands of colors, fine art offset lithographs need so
many extra inks, or “spot colors.” Technical reasons aside, the answer is
simple: artists paint in so many layers with so many colors that it is
impossible to accurately duplicate their works with just the four standard
process colors. In many paintings, the mid-tones can be easily reproduced using
the process inks alone. But without extra colors to bring out the highlights and
deep shadows, not to mention the pure pigments many artists use (which are
nearly impossible to copy using the four-color process alone), the resulting
print would be flat and lacking in color intensity!
Since the lightest highlights and deepest shadows are,
in general, the last areas an artist paints, applying spot colors after the
basic four gives each print added dimension. The “spot colors” make light areas
lighter, bright colors brighter and dark areas richer. In short, these extra
colors make the fine art offset lithograph the best possible method of
reproducing an original painting. They are the finishing touches that mean the
difference between an ordinary offset lithograph and a masterpiece.
If you think of an offset lithograph, as it relates to
the art world, as the highest quality reproduction of an original painting
attainable by man, then you have a clear understanding of why an offset print is
the best way to reproduce art.
The Fine Art of Offset Printing
The first step in making an offset lithograph are the
responsibilities of the artist and the publisher. The artist must paint a work
that collectors will find appealing, then the publisher must determine the
edition size and the image size. After these decisions are made, the original
artwork can be delivered to a printer who will begin the painstaking printmaking
process.
Production begins with photography. Until recently this
was done by hand, which is still used, although less often. This process uses a
series of color filters, with which individual negatives for each of the four
process colors are produced in cyan, yellow, magenta and black. Then the
negatives are mounted, one at a time, to a piece of clear glass and the negative
images are projected through a camera lens and a grid pattern (similar to a
screen door). The result is a dot pattern known as a halftone or screened
positive. One positive halftone image is created for each of the four process
colors. Then proofs are made, compared to the original artwork, and corrections
made.
If the proof shows a lack of color intensity in a
specific area, the rest of the image is masked off and the corresponding dots
are increased in size. If the proof shows that an area is too intense in color,
the dots in that area are decreased in size.
After these corrections are made, the film is
“stripped,” or mounted and aligned so that all four colors register perfectly on
the press. When the stripping is complete, each film positive is ready to be
transferred to a metal plate.
To transfer the film to a metal plate, it’s placed
against a thin sheet of aluminum that has a light-sensitive coating. Using
powerful lights, the dot pattern for each color is transferred to separate
plates. Then the plates are submerged in a developing solution. When removed
from the solution, the dot image is visible on the metal plate.
This method is still used by many printers today,
however, with the advent of new computer technology, the trend is to do all the
pre-printing steps digitally before the plate-making using a computer. In either
case after the plates are made both of these techniques follow the same basic
printing process.
The plates can now be mounted on their corresponding
plate cylinders inside of the printing press. An inked roller within the press
covers the image on the plate and then a water roller washes across the plate.
The water adheres itself to the areas that lack the ink, including the tiny
areas between the dots. Then a rubber roller picks up the image by rolling
across the plate, which is in turn transferred, or “offset,” to the paper. This
procedure is repeated for each of the process colors — cyan, yellow, magenta and
black — and the result is a four-color, or full-color, proof.
When a four-color magazine or brochure is printed,
approval of the four-color proof is given, in most cases, right away. But, with
a fine art offset lithograph, additional inks may be needed to bring out the
colors of certain areas. These are called spot colors or touch colors. This is
the biggest difference between a fine art offset lithograph and any other
printed product that is created using the process of offset lithography.
These extra colors help produce a more accurate
reproduction of the original work of art. They can intensify a specific area of
light color, dark color or unique color. And, each time a spot color is needed,
the technicians must repeat the masking process, create new plates and pass the
paper once again through the printing press.
At this point, a proof is normally forwarded to the
publisher, who usually consults the artist for final revisions. Once the
reproduction is approved, the final press run commences.
Why is it Called An “Offset”?
“Offset” is another word for “transfer.” In
offset lithography, a large rubber roller passes over an inked printer’s plate
made from a photograph of an original painting. This image is picked up by the
roller as a reverse image and the impression is transferred to the paper as a
positive image. This transfer, or offset process, reverses the original plate to
keep the image from being duplicated in reverse.
To better understand the theory, think about how a
rubber stamp works. When you look at a rubber stamp it is a mirror image of the
words or image that you want to apply. However, after the stamp is inked and
pressed onto the paper, it appears right-side-up, just the way it was intended.
Destruction of the Printing Plates
With original printmaking methods, the plates are
deliberately scarred or destroyed so no other reproductions can ever be made
from them, thereby protecting the integrity of the edition. Etching plates are
placed in an acid bath, serigraph screens are cleaned off, and the blocks used
for stone-lithography are broken. However, with offset-lithography, no conscious
effort to destroy the plates is necessary. The fragility of the plates causes
them to bend and crimp when they are removed from a printing press. They are
unable to physically be used again.
Offset lithographic plates are made of very thin
aluminum and a separate plate is needed for each color. After the plates are
created they are bound tightly around a cylinder and the process begins. When
the process is finished the plates are taken off the cylinder in preparation for
the next colors or the next job. If someone was to gently remove the plate with
the idea of perhaps using it again, they might spend hours trying to get it off
without it bending or crimping. It’s a very thin aluminum. Then they’d have to
spend hours again carefully reattaching it. In reality it would be fruitless. If
another plate was warranted, it would only take an hour or so to create it.
After the plates are removed, they are generally folded up and recycled.
The integrity of offset lithographic editions is more a
matter of ethics. In order for a publisher to earn the loyalty of the public,
its artists and its dealers, they must keep their edition sizes authentic and
legitimate.
Distinguishing Traits of Fine Art Offset
Prints
Determining whether a fine art print is an offset
lithograph or another type of print can be quite easy if you know what clues to
look for. One of the simplest things to look for is copyright information
printed in the margin. Generally, it will appear as crisp type, similar to the
type produced by a typewriter. Very rarely will any copyright information appear
on a stone lithograph, etching, serigraph or any other print produced using
other well-known printmaking methods. The copyright information usually includes
the title of the piece and the artist who created it, the publisher’s name and
address and the year of its creation. You may also see the universal copyright
symbol “©.”
Upon inspection with a magnifying glass, an offset
lithographic image is made up of tiny dots. The most evident dots will be from
the four main colors used in the processing — cyan, yellow, magenta and black.
Also, upon inspection it will be noted that the edges of the image generally
appear hard and straight without any blurring or coloring outside of the lines.
The registration (lining up of the colors) will appear perfect. And, the ink
used will appear to have no texture.
Another indication that the print may be an offset
lithographic print is the way the colors rest on the paper. They’ll be clearly
on the same plane as the paper. There will be no distinguishable overlapping of
color and only rarely will there be any embossed or debossed areas. Make sure
there is no embossed or debossed area because on rare occasions a publisher may
emboss or deboss areas, or an entire, offset lithograph. This is a special
effect and is not a result of the actual printing process, but rather a
manipulation of the paper after the image is printed.
Overall, the use of a magnifying glass can provide you
with conclusive evidence that the print in question is an offset lithograph. If
the dots appear, you should feel confident that you’ve uncovered the printmaking
method, and there’s really no need to examine the print further.
CLICK HERE TO CONTINUE
|
