The published articles are meant to primarily educate the students in printing to supplement their knowledge in the field of Printing. These are not simple Glossary of printing terms, but to the extent possible every term has been explained in brief so that it can be of some use to the students who appear in some sort of examinations and interviews.
I served the Printing Industry for over 40 years
in various capacities, a major part in an Security Printing Organization. In order not to waste the printing and paper related knowledge which I gained over years, I decided to keep them in public domain for the reason stated in prepara. Most of the illustrations - over 90% - have been generated by me to explain the terms suitably.
While I am not sure to what extent the published content will help, if the content is going to be of use to some one in some manner, I will be greatly satisfied.
Your views may be sent to me (
nrj_1945@yahoo.com) for my record and correction wherever needed.

TOTAL NO OF PRINTING TERMS

POSTED TILL NOVEMBER, 2012

- Over 400 terms-

Click on this line to read from 'A'

Saturday, August 25, 2012

Alphabet- A


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

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