1. Artwork: The original piece
of copy containing illustrations etc either received from the customer
or prepared in the press room for a print material. The art work –either
in black and white or colored format- may include all graphics, text,
illustrations & photos or will have only typographic matter. Only
when the art work is finalized and approved by the customer, further
processing of the same to bring it in print form will be carried out.
2. Acetate: A
transparent plastic base material used in graphic arts designing and
printing press for variety of reasons. The Acetate film, a specific type
of plastic material called cellulose acetate comes in various
thicknesses. The uses are many. The acetate film is used to make key
templates / layouts based on which the negatives, positives are
assembled for processing plates for printing. Like assembling the
negatives and positives, the final proofs of the composed matter is
also taken out on a suitable paper and assembled on this film to prepare
process negatives. The designers place the acetate sheets over
originals of artwork to write instructions and\or indicate colors for
placement. Some of the photographic/process films are of acetate
base. Being transparent in nature Acetate films are also used on
photocopying machines to copy illustrations and other matter meant for
demonstrations through projectors. However since the dimensional
stability of the acetate base is not totally dependable, they are
avoided in perfect registered jobs in process work.
3. Acid-free Paper :
Paper made from pulp containing little or no acid is called acid free
paper whose pH value will be of 7 or a bit higher which is the standard
requirement of the Printing industry. The printed papers and photos
prepared on acetic paper may discolor or disintegrate more quickly than
they would naturally in storage. In short the acid free paper resists
the deterioration of the material from aging. The paper mill generally
use acids to bleach the pulp, especially where wood pulp is used to
remove the yellowish colour. Where the acid content has been more than
the desired level in the pulp, the paper turns out to be acetic in
nature. Such acetic paper cause problems on the printing machines. The
acetic paper interferes in drying of the ink, contaminate fountain
solutions as it is in direct contact with the printing plates through
which the effect slowly percolates into the fountain solution. The
acids act on the paper, shorten the fibers, causing them to become
brittle, discolor, and crumble into dust. The non acid papers are called
alkaline paper, archival paper, neutral pH paper, permanent paper and
thesis paper. Acidic papers deteriorate in a relatively short period of
time, and should be avoided for use for printed items that are intended
to last for many years.
4. Acidity/Alkalinity : This
aspect covers many areas in printing - from paper to chemicals used in
processing. The pH (potential for Hydrogen) measurement of paper
determines the degree of acidity and alkalinity in the stock that
influences drying of the ink on the paper surface. Readings below pH of
7.0 are acidic and above are alkaline. Most of the paper used for book
publishing and other printed materials where permanence is of
importance, has been alkaline paper, while the newspapers are generally
acidic based. Acid free, or pH neutral materials are always recommended
for making paper. The alkaline paper making process has been increasingly
adopted by paper manufacturers because it results in reduced water
consumption in paper making, facilitates waste treatment and saves
energy and materials costs. It is also cleaner and less corrosive to
machinery than acid-based paper making.
5. Additives:
Pigments, Varnishes, oils, solvents and wax apart from driers which
are added during manufacturing of the ink are called additives. Each
component has their own properties and are discussed under ink.
SEE INK
FOR MORE DETAILS.
6. Additive Color :
Color produced by light falling onto a surface, as compared to
subtractive color. The additive primary colors are red, green and blue.
Color reproduction is achieved by combining Red, Green, and Blue light
(RGB) in varying levels to produce a full color image. Red, green, and
blue are the primary colors of white light and they cannot be produced
by the combination of any other colors. When they are combined they will
produce white light. The combining of red, blue and green colors is
known as the Additive Color Process.
If none of the additive
primaries are present, the color is perceived as black. When two primary
colors of light are combined, a secondary color is produced. The
secondary colors of light are Cyan, Magenta, and Yellow (CMY). The
secondary light colors are also the primary colors of used to reproduce
color for printed media.
7. Alteration or AA and CA:
Any change made by the customer after copy proof or artwork has been
submitted for approval. AA stands for author’s alteration. The change
could be in the copy, specifications or in both. In the similar manner
CA meaning customer alteration is also used as a term for the same
purpose.
8. Anodized Plate :
An thin anodized ( electroplating technique) aluminum offset printing
plate used on small offset presses. The base plate which is generally of
tin are deposited with tiny aluminum pixels by electroplating process.
The anodized plates behave similar to aluminum plate used in the
printing processes. The anodized plates are economical for small offset
presses, easy to use and work well on the press. These plates could be
viewed as improvised version over Paper based plates which has their
backside laminated. Anodized plates are also reusable by recycling 2-3 ,
i.e by performing chemical graining (removing the old image) instead of
mechanical graining. The process of repeated erasing and reimaging
provides not only economic advantages but also environmental benefit as
well. Reusable anodized aluminum are imaged in the same fashion as
today's thermal-plate and provide the same level of printing quality.
9. Anti-offset Powder/ Anti set off sprays : Fine
powder lightly sprayed automatically with a spray unit fitted on the
printing machine. The anti spray powder is sprayed on the surface of
printed sheets- especially coated papers like art papers- to prevent the
transfer of wet ink from the printed sheet to the back of the sheet
lying on top of it. The anti-set off sprays do not act as dryers, but
the purpose is to provide a cushion between sheets i.e an air gap which
will help prevent set off. A powder, commonly used as anti set off power
consists of fine starch particles that range in size from 10 micron
to 15 micron. Anti-set off spray is mostly used on letterpress
machines. The powder particles absorbed by the ink solidifies. Since
the use of anti set off spray powder causes dirtiness to the machine
parts use of anti-set off spray is discouraged as the present day inks
are supplied with anti set off qualities thus eliminating the use of
anti set off sprays. There are different grades of anti-set-off spray
powders, to cater for different types of substrate with different
absorption rates of the printing inks are being used. Printers with
Rotary Presses including rotary letterpress, Web offset, Flexographic,
Gravure, and Silk screen printing etc use UV cured inks instead of
using anti set off spray system.
10. Antique Paper : Rough
finish paper that gives the look of an age old paper is used on
Printing machines. In short the paper with antique finish is the rough
texture paper used as offset printing paper, and has a natural rough
feel with a random texture. Little or no calendaring is done to the
paper. The antique paper is used for printing vintage postcards, books
of poems, advertisement material, wall posters, greeting cards etc.
11. Art paper : High-quality,
relatively heavy printing paper, coated on both sides with material
something similar to china clay or chalk powder to give a smooth
surface. Such coating fills the miniscule pits between the fibers to
give them a very smooth and glossy surface. Reproduction of finely
registered multicolored images requires a paper that possesses an even,
closed surface to take on the printing inks uniformly. Its smooth
printing surface and quick drying contributes to a true color
reproduction. Different levels of coated paper like light coated, medium
coated and heavy coated papers available in the market are put to
different uses such as printing of Greeting cards, Advertisement
material, Annual and other Reports of the companies, high quality
Magazines to give gloss over their surface .
12. Antistatic Rod : The
attachment of anti static rods prior to deducting units at the end of
the the feeder boards will help eliminate paper dust affecting the
print quality. Such an attachment is usually in the form of a rod
running across the feeder board or form part of the dedusting units. The
function of these rods are to remove the static generated between few
sheets traveling one below the other on the feeder board. When
the static electricity on the paper surface is removed, the vacuum
sucks away the loose floating dust and dirt from the surface of the
paper and deposit them in a dedusting collection box. Usually the
static affected papers refuse to release the dust and dirt particles
from the surface thereby causing them to stick to the blanket surface
which in turn cause voids in the printed areas of the sheets. Printers
call them paper fluff which continues to print void image till the
machine is stopped and blanket cleaned to remove the dirt.
13. Automatic Blanket washing Unit: The Offset blankets
are normally cleaned at regular intervals
to remove the dirt and dust accumulated
over their surface which used to affect the quality of the print. Whenever the
blankets need to be cleaned, the machine had to be stopped, Plate and the
Blanket cylinders disengaged, printing unit opened and blankets cleaned with kerosene or
some blanket cleaning solution soaked cotton rag and made to dry by wiping with a clean
cloth before engaging the machine for continuing the production. However in order to facilitate easy cleaning even as
the press is running, automatic
blanket washing units have been developed which can be fitted on the machine. Such attachments clean the blanket with
automatic spraying of the solution, cleaning with a row of brush, and then wiping with a towel wrapped like roller system – all synchronized in one unit without affecting the print quality. This technology requires no towels or rags to clean blankets each and every time. Several models are made available in the
market which can be tailor made to suit each type of machines.
............Additions to alphabet A to be continued under A/2 later when compiled