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'

Sunday, September 30, 2012

Alphabet- O /2

Oxidation: One of the chemical reaction in which certain chemicals react with the Oxygen content in the air and polymerizes or changes their physical and chemical properties. In the process of drying of the inks, one of the processes used for the drying of the ink is the Oxidation process that allow the vehicles in the inks to absorb the Oxygen and dry on the substance and binds with the material on which the ink is printed. Oxidation does not evaporate, it only polymerizes and binds with the material.
Outsourcing: The term implies that certain wok is got done on contract with some of the agencies. Outsourcing is the act of a firm contracting with another firm to provide services that might otherwise can be performed by in house workforce but in many cases there are financial advantages that come from outsourcing the work. For example many of the medium size presses may not have all the facilities or sufficient work force to undertake all the processes involved in completion of the printed work. On certain occasions it may so happen that some jobs may be received which will generate much profit and part of them can be easily done in the press itself and part to be got done on contract. In such cases the presses outsource the partial work on prevailing market rates and complete the remaining work in the press itself to raise invoices on the press name. Outsourcing in stricter meaning is the delegation of one or more processes to an external agency, who then owns, manages and administers the selected processes to an agreed standard and cost for particular period of time.
It is not necessary that the portions of the work is always physically sent to the firm with whom the work has been entrusted. Even certain portions of the work are got done inside the premises of the presses with labors from the outsourced agencies. Another example is the Printing machinery and equipment manufacturers often outsource fabrication of a certain components of the machine with their name tag, with firms who are experts in the manufacturing of the said part. This reduces the overall cost of the machineries and equipments to a great extent. Some of the work outsourced by the presses publishing the books include proof reading, editing, process work, plate making, and binding.
Off color: The color or shade which is not actually the original or standard color of a material. When it is stated ‘Off White Color’ it implies that the whiteness of the material will be a bit less compared to standard white color. Since the shade can not be expressed in terms of percentages, the word ‘Off’ is prefixed and expressed. For example ink and Paper manufacturers say Off Red color, Off Blue color, Off Grey etc to some of the special shaded tints manufactured as proprietary color for a particular firm.
Onion Skin : A lightweight paper usually used in the past air mail stationery. Such light weight paper is used on typewriter machines to produce duplicate and triplicate copies. Since they are light weight thin papers, the carbon copies obtained on the typing machines used to carry clean image . The copies made on Onion skin papers are used for record keeping purpose since the volume being thinner, they occupy less space. The name Onion skin paper is given due to its translucent surface which resembled to that of onion skin. Though lighter in weight due to the thick formation of the cotton fiber content, the paper is found to be durable.
OEM: The expansion of the three letters OEM is Original Equipment Manufacturer. Some of the original machineries and equipments may require ancillary equipments and units to support its function. It is possible that those ancillary equipments may not have been manufactured by the OEM who supplied the main machine and belonged to another group of OEM though it may not bear the label to indicate so. Without those ancillary equipments it may not be possible to work with the main machine. In such an event can the supplier of the main machine claim themselves as OEM for the set of machines? Legally speaking, yes, because the main machinery function is linked to the function of the ancillary unit and therefore the machinery design being the design of the main OEM, the ancillary unit too belong to them.
To understand the implication of read the following example:
Supposing a special functioning printing machine is supplied by a manufacturing firm called Stephen under brand name (Proprietary product) “ Beep Print” .
The machine function is linked to a ancillary unit manufactured by Siemens, Dell, Nokia, Philips or some electronic group. Some of the parts inside may have software with instruction inputs of the main machine. Some of the components of the ancillary unit may be of general items in nature and easily available in the market, and some parts may have been specially made for the Beep Print machine function. Still Stephens will only be considered as the OEM of the Beep Print along with its ancillary unit, as both the main machine and the ancillary units are interrelated and function as one unit.
OCR or OMR: Optical Character Recognition (OCR ) or Optical Mark Recognition (OMR) is an imaging technique where by the typed text, any printed matter and even the hand written texts are scanned, copied, and translated into editable word version by special software. The Optical character recognition software allows a computer program to convert handwritten or scanned letters into digital image and then with OCR software they are converted to readable text. The OMR imaging process utilize the OCR or OMR device to electronically translate the characters into codes which can then be saved as a text file thus eliminating the need for key boarding of the texts.
The printed matters can be quickly converted to text for re use thus avoiding retyping of the matters. Even PDF with tables can be converted to re-editable word document. Some of the Online sites offer free service to convert the documents on trial basis. The benefits of OCR or OMR technique is:
  • Large volumes of printed matter can be converted easily into word document without involving retyping of the entire text.
  • Speeds up the working process.
  • Reduces the cost
  • Need not keep the entire documents in storage or keep the books stored occupying lots of space . As and when needed they can be converted for updating or reprinting.
However one drawback seen in this process is that some of the converted version may not be 100% dependable and some words may have to be typed physically as the system fails to read and convert un recognizable words or sloppy hand written matter. Therefore the converted version will have to be gone through at least once to verify the converted text. 

Orthochromatic : The type of Photographic film which is sensitive to all rays of the wavelengths except Red. Therefore processing of this film can be comfortably done with Red safe light ion the dark rooms. This is best suited for processing black and white pictures.
Oblong : The term describe the print material that are printed to read on the longer side or bound on their shorter side like Albums, story books, catalogs etc instead of on the longer side .

Saturday, September 29, 2012

Alphabet - O

1. Overrun: - Production of print copies more than the ordered quantity is called Over run. This may occur due to inadvertent error in judgment of the printer expecting reprint order, or over printed by mistake due to technical fault on the machine. The over production of printed materials occurs due to one specific reason. When the books are printed, say for example order for 10,000 copies of 100 pages each. Since the printer can not exactly print 10,000 prints alone to get all good sheets, is always customary for the printers to print something like 5 to 10 % extra copies as spoilage which can occur in subsequent printing. Sometimes it may so happen that at the end of printing and binding, due to lesser amount of spoilage than the anticipated spoilage, the quantity of finished product may go up by 3-4 % . Such excess product will be termed overruns and the excess quantity may be offered by the printer at some concessional rates than the actual rate that is charged. An overrun is just that there are more prints than you have ordered. Similarly due to unavoidable reasons when the spoilage had worked out to be more and the supply had to be restricted by 2-3% then it will be called as under run. Therefore in the printing industry where such work is regularly undertaken, the contract provides for the excess or short supplies by 3-5%.
While the above Over run factor is in commercial side, another meaning of overrun in technical side is that the type setting that had exceeded the estimated no of pages due to the picture blocks occupying more space than anticipated and the typed matter had to be rearranged from one column to the other to accommodate the print matter. This is also called Over run.
2. Offset Printing : The technique of printing that transfers ink from a plate to a blanket to paper instead of directly from plate to paper is called Offset printing. This is one of the three main processes in Printing. The Offset printing again has two divisions . they are called Wet Offset and Dry Offset printing. In Wet Offset printing the plates used for printing has the images and text matter in plain surface. They are neither in relief form, nor etched inside the plates and are in the same surface level of the plates.
In Dry Offset printing the plates used for printing has the images and the text in relief format similar to Letterpress printing, with one basic difference. The image will be in readable form unlike in letterpress which has the matter in reverse format. However both Dry Offset and Wet Offset printing transfer the inked images on to the paper through rubber blankets only.
Several models of Offset machines are available right from printing  A4 size papers (Like Swift, Multilith, Romayor and Rota print machines)   to print bigger size sheets and even reels of paper. Of late the Dry Offset Printing remains the main medium of printing for printing Currencies as the working is found to be more easier than   wet Offset printing.

3. Opacity : The degree to which light is not allowed to travel through a substance is called the opacity of the substance. This term applies to the paper and partly to the film  in the printing industry. If the opacity of the paper is more it will cause show through i.e showing the front side printed matter onto the back side of the sheet of paper. Therefore opacity of the paper is important in printing. Papers that contain more fibers, degree of bleaching of the fibers, and the kind of coating etc  have the ability to hold a printed image without showing on to the backside. The thickness of the paper also influences the opacity. Note however that the thickness of  paper alone is not sufficient to increase the opacity, some times even the thinner paper will have more opacity than the thicker paper because of the fiber and filler contents.
Opacity in simple term is a measure of a material’s ability to obstruct the passage of light. Sufficient opacity is important to prevent printed text from showing through in a harmful manner on the reverse side of a paper.
Opacity is determined by a ratio of reflectance measurements which is the measure (percent) of the amount of light passing through a sheet of paper. Several instruments and equipments are available in the market to test the opacity. The general principle is that the paper with a black object kept at the back is  illuminated from the top side  at a particular angle and the reflected light measured. Similarly the same paper with a white background is measured without altering any of the setting. The difference between the two is compared to work out the opacity of the paper.
In respect of films used in the process work, the opacity is indirectly termed as density.

4. Opaque: The term Opaque has wider meaning in printing. An object which is not transparent or translucent is called opaque object. In printing this term refers to process films and inks. Opaque is certainly not a color, but indicates the light passing ability of the material.
When a negative is made ready to make plates or blocks for printing, due to some extraneous factors some of the non printing areas may have got transparent spots in the film which if allowed to remain blocked can pass the light during plate making process thus causing spots to appear in the non image areas during printing. In order to stop those spots from appearing in the non image areas causing unwanted images, the spots are blackened out on the negatives with a special retouching medium called opaque ink which will be in dark reddish colour. The opaque ink will stop the light passing through its surface. This is called Opaquing process. However if the entire non image areas in the negative are not fully black and somewhat translucent due to improper exposing or developing the opaquing process can not be done.
Similarly printing inks too have the quality of opaqueness as their property. The printing inks are broadly categorized as opaque inks and transparent or translucent inks. The process inks used in three or four colour inks are translucent as they sit on top of one another to create secondary and tertiary colours in the print to resemble the original colored image. If the colors used in the process inks are of opaque colors then they will block the previous ink color on which the subsequent inks have been printed thus producing one single color image  instead of multi color image. At the same time opaque inks are also used in printing for some work. For example all the metallic inks are opaque inks that gives particular shiny shade are used for certain jobs. The ink used in the screen printing process are all  opaque color inks. 


5. Overlay: This refers to the packing given over the bed of the printing machines to rectify the weak image appearing during the impression. Such overlay is done during make ready process. The Type fonts are of 0.918” height and due to constant use they may have worn out and cause slightly weaker print when composed with other type fonts. Therefore wherever such defective print is seen, to rectify the defect  two types of actions are taken. One is underlay and the other overlay.  Small paper strips  pasted at the back of the composed matter to bring them to correct height or placing some kind of packing material below the form to bring it to normal height in Letterpress printing. But the same defect can be rectified by overlay process by pasting small strips of paper over the impression bed in the platen machines or the impression cylinder covered with the packing material that contacts the typed matter or blocks locked in the frames. Note that individual type fonts (letters) can not be underlayed and only a portion of them can be adjusted. However by overlay process even such small adjustment is possible. Similarly the areas in the blocks which show weaker print is also rectified by overlaying in the weak areas  by pasting different thicknesses of paper on the impression bed. Since such an under laying or overlaying process is not possible in the Offset printing process (whether Dry Offset or Wet Offset) i.e to place strips  of packing either at the back of the printing plate or on the impression bed, to rectify such problems  the packing is given under the blankets to adjust the weak image which  that is called under packing- a modified version of  to underlay or overlay. 

Friday, September 28, 2012

Alphabet- N /2

7. Numbering : The numerals printed on a print material by a set of boxes or a single box that contains numbering wheels are called numbering. Numbering is a wide subject to describe, but in printing what is referred to as numbering is the printing of numbering on lottery tickets, currency notes, invoices, vouchers, bill books and variety of such print material where accounting is kept. The numbering is done both manually and using automated machines. Hand numbering is always done in ascending order since the quantity of such work may be limited. However where huge quantity is involved the numbering is always in descending order by automatic machines.
One of the important aspects that one should understand in numbering is the sequential numbering and random numbering both on individual sheets or in multiple up sheets. Sequential numbering is the process of printing numbers that begin with a given no and subsequently ends with the required end number.
For example when you start hand numbering for small quantity of jobs from 001 and further go on like 001, 002, 003 till the end number which is required to be produced is printed, say 999 such a process is achieved it called sequential numbering in ascending order (See the illustration -1).
Since the sequential numbers can be printed in either ascending or descending order the choice of printing in ascending or descending order will depend upon the quantity to be numbered. Where huge quantity of copies are needed such jobs will be numbered in automatic machines in the descending order i.e beginning with numbering the last number first, so that when the required number is printed and completed, the top of the printed sheet will show the starting no. (See the illustration -1). 

Another example of numbering huge stocks are numbering in multiple ups. Supposing one million lottery tickets are to be printed in one series, they will not be printed as one up format. The tickets will be printed in multiple ups most suitable to the sheet of paper used and then the numbering done in descending order (See the illustration-2 ) since printing individual ticket will consume not only more time but will also be not economical. Numbering Bank Notes too fall under this category. 

The random numbering is another process that is adapted in Bank Note or Currencies or Raffle ticket printing where the defective notes or tickets in a bundle is separately printed and defective notes/ tickets replaced.  Supposing one million tickets have been printed in sequential no, and some have been found to be wrongly printed or found with damaged numbers, they have to be separately numbered and defective tickets replaced.  Since they may belong to different bundles bearing different nos, numbering of such isolated  prints can not be done as sequential numbering process and have to be numbered individually.   The  numbering  of such print is called random numbering (See the illustration-3). For the random numbering single note numbering machines called Nota numbering machine or random numbering machines are  also tailor made for the user industry and given by the firms of repute. Such machines are again not freely available in the market and are proprietary products of some of the firms.  The single nos will be printed based on the input fed in the computer attached to those machines. 

8. NCR Paper: The abbreviation for NCR is No Carbon Required paper, a brand name given for carbonless paper. The working principle of the carbonless paper is simple. The NCR papers are coated on the back and front sides with certain special chemicals. The micro-capsules of the chemical react with pressure of the pen and change its color in those areas pressed and form a color dye. Since the capsules are so small, the print obtained is very accurate. The NCR papers can be used on Dot matrix printers too, but can not be used on Laser printing machines. The NCR papers differ with other printing papers in respect of thickness. If the multiple copies are required in an invoice book, thicker paper can not be used and therefore the NCR are manufactured on thin varieties of paper below 40 gsm or so. (Also see Carbonless paper).

9. Note sorting or note inspection machine : These machines are used by the banking industries and the currency producing presses and Raffle ticket printing units to segregate the defective and counterfeit printed material. While the Banking institutions use these machines to segregate the spoiled, soiled and counterfeit notes, the Currency printing units and the Raffle ticket printing units use a bigger size machine of the same nature called inspection machines to inspect the sheets and either separate them as sheets with defective prints by marking the defective prints so that they can be later random numbered and replaced or treat them as spoils. This process of note/ticket sorting is aimed as cost saving measure against manual labor.
The note sorting machine software will be programmed to suit the specific requirement of the banking institutions like segregating the genuine and fake notes, or segregate one specific group of notes and the other group of notes. (See illustration to understand the function). As for the Currency note printing units, and the Raffle ticket printing units, the software will have all the details of the notes or tickets including the security features so that they will be compared with the master image stored to direct the machine to accordingly act in treating them as good or rejects. For Currency printing units and raffle ticket printing units the machines are custom made by specialist firms of repute and are not freely available elsewhere. Varieties of note sorting machines for banking institutions are however freely available in the market. 

10. Non reproducing Blue: Certain colours can not be recorded easily by photographic means. One such color specially made is called Non reproducible light Blue called NRB. NRB does not record on graphic arts film, and therefore used to write instructions on layout sheets and originals, however at the sides without interfering with the work. Since NRB color and the white background are indistinguishable to photographic film, the NRB is not captured as an image by the film.
11. Nominal weight: The weight stated as the basis weight or the substance weight of the paper. The invoices are always raised on the basis weight of the paper and therefore tolerance of plus or minus 5% are always accepted in the industry.
See this example. Supposing order for 80 gsm thick paper is ordered, the paper mills can not ensure 100% thickness in all areas and therefore in some areas it may measure 80 gsm while in some areas they may measure 80.5 gsm or 79.5 gsm with minor variation in acceptable limits. However the nominal weight of the paper will be treated as 80 gsm only.

...........Additions to alphabet N to be continued under N/3

Thursday, September 27, 2012

Alphabet -N

1. Nested : Keeping the Signature marks remain in hiding, the sections of the books are assembled in the proper sequence for binding is called Nesting. This is also called nested. The signature mark is a letter, number or combination of either or both, which is printed at the bottom of the first page of each section of the book. Since each book of several pages will have several sections it is to be ensured that the pages and sections are placed in the correct sequence order before binding. Therefore to help the binders gather the sections of the book in sequence an identification mark that tells the sequence like 1,2, 3, 4 or A, B, C, D etc are printed as signature mark, but at the same time the printed marks should not be visible after the books are bound, lest it will mar the appearance of the book and therefore they are nested. 
2. News Print : Paper made of mechanical pulp or wooden pulp. The Newsprint is a low quality paper meant for the paper used in printing newspapers and weeklies and monthlies with mass circulation besides telephone directories, comic books, trade magazines etc. This paper is considered to be low quality in terms of strength and durability and has shorter life span . They are manufactured mostly in off white color or slightly brownish due to the use of wood in the pulp. However good quality newsprint paper is manufactured by bleaching the pulp with certain chemicals in the paper making mills.
3. Newton Ring : This is one of the processing defects that occur in contact printing like making negatives, positives or photo prints. The image shows irregularly shaped patterns, something like bubble or oil spill on the surface of the water. This is due to improper contact where in some amount of air remains between two contacts. Newton rings arise when two smooth surfaces like glass and film are in position during contact. This problem also arises during scanning process. Due to invisible air bubble the light from the enlarger or the exposing lamps refracts into a rainbow pattern as it passes through the surface such as glass or film. This will leave bubble like appearance in the processed material. Waves reflecting from two surfaces can interfere constructively and destructively and such an interference will produce a concentric ring pattern. This defect will be visible only when a film negative or positive particularly that of an halftone image is transferred by contact or in a photo print which is made and developed from the negatives. Note that the defect will vary in content and size with each print from the same negatives as the air block can change position . if the glass is cleaned and worked the same defect may continue to occur if the film or the photo paper used and the glass frame are too shiny or smooth surfaced. If the defect continues to come in the processing department, they try to switch over to optically coated glass frames which of course will cost bit more. 
4. Nipping : In the book binding process, the folded sections are either sewed, stitched on sides or wire stitched. Since the folded edges of the sections will be bulgy at the back side (Spine) where the stitching takes place, it is necessary to remove the air from inside the sections that causes the bulge and make them lie flat. This is done by keeping the folded book ready for binding in hard-press and tightly press them giving hydraulic pressure to flatten the edges. Thus the process of destroying or knocking out the bulge of the back side of the book before sewing or stitching in binding is called Nipping which is a bindery term. Dictionary meaning of nipping is destroy. 

5. Neutral pH : The pH scale is from 0 – 14 . The scale below 7 is called acetic and above 7 are alkaline. Therefore the range of 7 is called neutral pH. The pH plays an important role in many areas of printing. The main material in printing, the paper is mostly manufactured with pH values in acetic range to increase the stability, facilitate ink absorbency, drying and to improve the permanency for printing of archival records. The pH also plays vital role in Offset printing process where emulsification of the ink takes place due to the dampener solution becoming acetic. Pure water is neutral, with a pH of 7.0. When chemicals are mixed with water, the mixture can become either acidic or basic. Chemicals that are highly acidic are called reactive chemicals and can cause burns. These chemicals can cause severe burns. pH is measured by either test strips or special apparatus available in the market.
6. Negative: A process photographic film that records the originals in reverse format i.e the black areas in the original remaining transparent and the white and bright areas in black. In short, the term negative denotes a photographic image that reproduces the bright portions of the photographed subject as dark and the dark parts as light areas. A transparent plastic film surface is coated with different chemicals and material like metallic silver that changes their properties in invisible manner when exposed to some light source. The invisible change that takes place is due to the reactions of light . When treated with another chemical the invisible changes will become visible to show the images in negative format. Different types of films are produced by different manufacturers to reproduce good negative processed in different manner. When the image from the negative is transferred on to a plate and printed, they reproduce the image as per the original format. In the photo lithography and printing processes where blocks are made, unless a film negatives is prepared the printing process can not continue. The negative is not a term to represent processing the black and white originals alone, even the colored originals are processed to produce negatives in black and white. When the photographic camera films are processed, the processed negatives will show colored images but in negative format. 
............Additions to alphabet N to be continued under N/2