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 ( for my record and correction wherever needed.



- Over 400 terms-

Click on this line to read from 'A'

Wednesday, August 29, 2012

Alphabet- B

1. Backup: To print on the reverse side of a printed sheet.
2. Binding: The process of fastening both loose printed and non-printed sheets into some sort of a book, magazine, students note books, writing pads, brochures, booklets, catalogs or any print books by using coils, wires, staples, or some sort of good adhesive. This process is the last step in the press process before dispatch. Binding also includes operations such as sorting out the good and spoil sheets, gathering the good sheets together/arranging the printed sheets in correct sequence which in technical term is called collating, then drilling small holes for stitching or stapling and finally cutting/trimming to desired size etc, if it is meant to be finished in a book format. Technically in a printing press any one of these operations falls under Bindery work.
In order to preserve the frequently handled books of achieves, books preserved in libraries for references and old books of importance etc from getting damaged, such already fastened books are once again opened out, restitched and outer covers replaced with a firm leather or rexin case covers (wrapped) to preserve them for long run by this process. There are many types of binding and each type deployed depends on the nature of the material required to be bound.
3. Blanket: A heavy rubber coated material used in the offset printing press to transfer ink from the plates to the paper. A fabric-reinforced sheet of rubber is fastened to a cylinder on an offset press, which receives ink from the plate and then transfers it on to the paper. These blankets are made of supporting fabric and a rubber composite. Various rubber materials are used for manufacturing the blankets which are of different qualities such as compressible blankets to hard finish with their surface either smooth or little rough. While most of the printers prefer to use compressible type of blankets slightly rough blankets are also used by some of the printers, but that depends on the type of machines they have as hard blankets have less contact with the paper surface thus reducing blanket contamination. Offset compressible blankets are constructed with two, three or four plies of a strong woven fabric fastened together with thin layers of rubber coating. The number of fabric layers equals the number of ply. For example two to four ply blankets would have two to four layers of rubber coating on them. To make the blanket compressible a thin uniform layer of air cells (for compression) is layered between the fabric and rubber face. The blankets should be free from pinholes, and blemishes which could affect print quality. The surface should also be non-abrasive to reduce plate wear. A good quality blanket will have the following qualities:
(a) Resilient: uniform surface hardness and hard enough to be capable of reproducing a facsimile of the printing image .
(b) Good Surface: very smooth or having a matte surface with no low spots or raised areas.
(c) Resistant: It should be resistive to all kinds of ink, cleaning solvent and varnish used on the machine. But at the same time the blanket should be ink receptive failing which image transfer will be affected. The blankets should be resistant to peeling, blistering, embossing, debossing, glazing or tackiness, and also abrasion from paper or board.
(d) Good Paper release: The blankets should be capable of giving good release of ink and paper from its surface as well.
As there are many types of blankets available it would be in the best interest of the printer to evaluate the right type of blanket that suits his machine work.

4. Blind Embossing: A finishing process in which a design is formed into a sheet using a die causing a slightly raised image on the surface of the paper. Normally in blind embossing no ink is used to form the image. READ MORE DETAILS UNDER EMBOSSING.
5. Bleed: Printing areas that extend beyond the edges of the actual image required. When the printed sheets are finally trimmed one can see the images extended up to the edge of the sheet without showing even a hairline white margin around. Therefore where the images are to be kept up to the trimmed sheet, the bleed will be incorporated. Example: one can see the tints in the currency touching the edges without showing any white area.

Bleed allows us to print slightly oversize image than the actual image and when they are cut to exact size seamless appearance of the image bleeding off the edges can be noticed.
6. Bond Paper: No special meaning be attributed to the word Bond in the Bond Paper. This term came into existence during first world war when binding settlements called contracts or Bond between two parties were written on hundred percent cotton rag paper embedded with water marks to preserve them for long years. Slowly the business community too were inclined to use such durable paper for their correspondences, contracts etc which needed to be preserved for long time and accordingly got wood free bond paper made of partial rag content manufactured instead of full cotton rag content (to reduce the cost of paper) but with a watermark that showed the manufacturers name or their brands. Such papers were termed Bond Papers.
The Bond paper is superior quality of strong durable paper used for writing, printing and photocopying work. Bond paper is generally used for letter heads, paper used for communication and contract . The standard Bond paper is manufactured either with full rag content or with half rag pulp and manufactured in white or off-white shades. Since Bond paper is a high quality durable writing paper similar to the paper used on currency or bank notes they are manufactured having more than 50 gsm thick.
7. Brightness: This factor relates to the reflective quality or brilliance of the paper which affects contrast in printing processes. Paper brightness is defined by the percentage of light that it reflects. Paper with a higher brightness allows colors to stand out, while lower-brightness paper is easier for reading or extended viewing. The brightness was introduced as a method to control the bleaching process during paper manufacture. The brightness of the paper is measured by special apparatus reading on a scale of 0 to 100. Two standards are in vague - one known as GE standard read by a special instrument developed by TAPPI (Technical Association of the Pulp and Paper Industry), a research organization. While the TAPPI standard for the brightness is accepted by U.S , the ISO standard (International Organization for Standardization (ISO) is accepted by European, Asian and other countries.
GE brightness and ISO brightness measurements differ with each other due to different angle and the reflected source of light used in both the methods adapted by them. For example if the brightness on ISO is 100 the brightness reading by GE will be 98 and if it is 89 in ISO it will be 79 in GE. This will illustrate that the factors expressed in both the units differ by two points only.
If the brightness of the paper is very high it may sometimes alter the print result. The brighter and whiter the paper is, the brighter and lighter the images are. Colors on less bright papers are noticeably darker.
One important point that needs mention here is the confusion caused by Brightness and Whiteness which are two different properties of the paper constantly confused by the industry. While the brightness is volume of light reflected back by the paper surface, the whiteness refers to the shade of the paper.
8. Blind Image : This is also called blind embossing with an engraved metal die. An embossed or stamped image on the printed stock without embossing with ink or foil. Blind embossing refers to an embossed image embossed exactly over already printed image on the page. In such cases the image is first printed and to give a three dimensional relief effect to the image, the same image is embossed from the back side of the printed sheet in perfect register using engraved metal die.
9. Body color: The main text or design area of work except headlines.
10. Broadside: This term refers to the large sheet of paper printed only on one side, matter readable on the longer side. Examples are printed posters, public event proclamations, wall hanging pictures etc. This term is actually known as broadside printing. Broadsides have been one of the most preferred printed formats at one point of time for printing the public announcements, advertisement etc which had to be read from a distance, at the same time should remain eye catching. Therefore very large fonts had to be used for printing broadsides. Printed on single sheets of paper and on one side only, the broadsides were often crudely printed as very large fonts made of metal types could not be used for printing. The large metal fonts being heavy and not easy to handle caused working problem and therefore wooden type faces were prepared and used in their places. Hence crudeness in the printed fonts noticed on such printed stocks.

11. Bronzing: The golden effect on the printed image is produced by dusting bronze powder over the printed wet images. This is done to give effect of metallic finish which is otherwise done by foil embossing technique or use of metallic inks. The bronzing process is widely applicable to Gold printing which is used in the production of high-class labels, wrappers, box tops, covers, greeting cards and other work where bright, showy effects are demanded.
The process involves, first, printing the sheet with a tacky colorless ink, and then dusting it with bronze powder which adheres to the printed image. Gold bronze powder is made from copper, brass and zinc alloy. Once the dusted bronze powder on the print gets dried It is then lightly burnished to smoother and brighten the bronze and the loose bronze is cleaned off the sheet. Small work can be bronzed by hand, but the work must be carried out under vacuum. Bronzing machines are also available for producing large quantities.
12. Butt Register : A technical term also called Kiss register where two images perfectly register side by side or one above other without showing even a hairline break. In this printing process two different colored images sit side by side very closely, but they neither overlap nor show even a hairline space between them. This term is actually applied in screen printing process.

13. Bursting Strength: This is an important factor that indicates the strength of the paper. The burst test is frequently used as a general guide to test the strength of paper, solid board and corrugated board. Bursting strength is usually quoted in kPa which is Kilopascal. Kilopascal is a metric unit and equals to 1000 force of Newton per square meter. This measurement is widely used to indicate the strength of paper stocks. While many countries indicate this factor as Psi which means Pounds per square inch, others express them in kPa both of which are tested with two different apparatus. But both Psi and kPa factors can be converted to Psi to kPa and vice verse by a simple conversion factor which is 1 kPa = 0.145037738 Psi. Be aware that the burst factor is inter related to tensile strength of the paper which is another factor that determines the strength of paper stocks. The Tensile Strength can be read under Para Tensile Strength.

............Additions to alphabet B to be continued under B/2  later when compiled

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