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, October 31, 2012

Alphabet - U

Underlay: On the printing machines when the impression pressure is not uniform, some packing in the form of thin paper is placed below the Impression bed or below the blanket to raise the non uniform surface on par with the level of plane surface. The process of inserting such packing material is called the Under Lay. On Letter press printing machines the localized packing is given below the impression bed to get more impression on certain areas. On Offset Printing machines the said packing is given below the blanket . On Offset machines sometimes uneven thickness of the blanket surface may cause impression variation and in order to rectify the defect the packing is given.
Particularly when the typographically composed matter with blocks are combined and printed, it may so happen that at some places the blocks may not be in level with the type heights. In order to bring them to type heights, packing paper will be pasted behind the blocks as Underlay.
Though the underlay refers to the localized packing to offset the image variation the overall packing is also done normally on the machine beds or blankets for the following reasons:
To compensate the varying thicknesses of Plates or Blankets used on the machines. Even though the plates and blankets are supposed to have uniform thickness, during manufacturing process, some thickness variation can occur and therefore they may require to be compensated.
To increase or decrease the desired print density.
To compensate the paper stretching which results in image variation in multi color printing thus causing mis register of subsequent printing. The said problem is compensated by adjusting the packing in plate and the blanket cylinders to increase or decrease the print length marginally. Adding or decreasing the packing under the plate or blanket cylinders will increase or decrease the diameter of the Plate or Blanket Cylinders by packing sheets. More packing under blanket cylinder will increase its circumference and lengthens an image, while adding more packing to the plate cylinder shortens an image. The procedure varies slightly depending on whether the press is a bearer-contact press or a non-bearer-contact press.

2. Unjustified: This word in printing refers to the composed text material not aligned perfectly on the right side of the margin while the same text material is pin perfect alignment on the left side i.e beginning from a fixed point on its left side. The said non aligned matter on the right side is called ragged to right or Unjustified typographic matter. Generally all the books and News papers will have the types justified on the right side to increase readability and to give pleasing look to the eyes. 
3. Underline: A thin line placed beneath every word is called the underline. This is also called Under Scoring. This is done to emphasize or give prominence to the word. When the underlining is done on multiple words that runs to few lines, the said process is referred to as solid underscoring process.
4. Under run: When the print order is received sometimes it may so happen that due to extraneous reasons or over spoilage or due to technical fault on the machines, less no of copies may have been printed on some of the pages against the total printed copies required. If the quantity is much higher it can be reprinted. But if it is marginally found lesser, it will not be economical to print the short run pages. Thus the total quantity of printed materials which were found to have been printed less than what was specified in the original order is called Under run.
5. Undercut: On an offset Rotary printing machines the Cylinders rest on bearers instead of on gears alone. The bearers can be seen as a metal ring like arrangement provided at both the ends of the Cylinders on which both the Cylinders revolve. However when both the cylinder bearer touches each other, some gap can be seen. The said gap is called Under Cut. The gap is due to the low circumference of the blanket cylinder compared to the bearer level of the same cylinder, which is provided to fix the blanket . When the blanket covered blanket cylinder touch the impression cylinder on getting the impression, the image gets transferred on to the paper surface. There will however be no under cut on the impression cylinder as it is not covered with any material and will remain as a smooth surfaced metal body. However note that the Plate cylinder will have undercut for fixing the plates to bring it to the bearer height to transfer the image on to the blanket cylinder. The Undercut has been made to accommodate both the Plate and the Blanket and to provide room for packing below both to adjust the image quality. 

6. Unleaded: Typographically when the matter is composed, no space will be provided between two lines by inserting a space called lead. Such a composed matter made ready for printing is called unleaded type matter. The lead consists of thin lead to thick lead of varying thicknesses to suit different jobs and they are called spacing material.
7. Upper case: In Typography all the capital letters of the type faces- are called Upper case letters and in the hand composing type case all the upper case letters will kept separately in the right side of the type case. The compositor, who is responsible for composing and arranging the letters to make it ready for printing would stand before the slopped two wooden cases which are divided into several boxes or sections to accommodate all the letter, both capital, small, capital and lower case letters and other symbols. Capital letters are stored in the Upper drawers and the regular letters in the lower drawers.

...........Additions to alphabet U to be continued under U/1

Tuesday, October 30, 2012

Alphabet - T /5

18. Teamwork: Team work means a group of persons joining together to complete a process from A to Z in specified manner as is required to be done. Every voluminous work requires a group of personnel to perform certain actions for its successful completion. Unless there is coordinated action to function as a team, the process will not get completed in an ideal fashion. Every team member is responsible for a set of action. For example in bigger presses the action of personnel for on time procurement, periodical maintenance, breakdown maintenance, oiling, greasing of machines, production related personnel in various sections, supervisory personnel, managerial personnel etc have to adhere to certain schedules and complete their work in the manner required. In addition to the activities Machines start time, Machine stop time, cleaning of rollers etc will have to be properly monitored, more efforts to control of spoilage, waste management etc are to be carried out. A clear system of signals should be developed to coordinate the press crew on various operations. Safety norms to avoid accidents are to be followed and monitored. Each and every crew members of the team must be educated to understand the signals to carry out the operations in a smooth manner. Therefore the personnel working in all the areas will have to function as a unified team to successfully complete each and every work to ensure accident free environment and to make the press profit oriented which will be beneficial to both the personnel as well as the press. The coordinated activities as above by the press force is called Team work.
19. Thin spacing: In typographic operation, some times it may so happen that inspite of attempts to justify the typed or composed text matter, some of the end to end lines will not adhere to the adjustment and show thin gap at the end. In order to offset the defect, thin spaces will be inserted between words to fill up the gap to bring all the lines justified to proper length. Such an action is called Thin spacing in typographic composing and similarly the insertion of gap in the photo composing process to justify the line is called thin spacing.

20. Tonal Compression : The process of reducing the tonal range of the original image from high dynamic range to limited dynamic range is called Tonal compression. This is done for two reasons. One to improve reproduction in printing and to enhance the color effect and the other for conserving space in the computers files in desk top publishing. When the tone compression is carried out, one can notice that the appearance of the image is not drastically altered except showing some variation in the color densities.
The tonal compressed images are necessary in the transparencies and color originals that are needed for projections through projectors because the standard LCD monitors and Projectors do not reproduce the full range of color intensities due to medium focal length lenses fitted on them. If you see the two images reproduced below you can observe that the image without tonal compression showed the size as 4.05 KB while the same image with tonal compression is 3.60 KB and there has been no noticeable change seen in both the images.

Tones not compressed / Size of image 4.00 KB

Tonal compressed / Size of image: 3.60 KB
21. Tint : Reducing the density of a colour to print it in lighter shade is called the Tint. This is achieved by adding white color with the strong color. The tint can be in the form of solids or very thin screen dots. The tints are generally printed as background color so that the darker color when printed on it will have contrast effect.
22. Tail edge: The back edge of the sheet of paper . The front edge of the paper is the one which is gripped by the grippers before entering into the printing unit and therefore is called the gripper edge .
23.Transparency: Positive version photographic images on film which may be either in black and white or in color is called Transparency film. Such colored transparencies are sometimes given as colored original to reproduce in the job given to the presses. The Transparencies are used as transmission color originals and color separated through the process cameras for making negatives or positives.

Similarly the transparent films with images or text matter used in seminars and conferences to project the same to the audiences are also called Transparencies. Such images on the Transparencies can be wiped out with some chemical solution for re use.
24. Tinting Medium: Tinting Medium is semi transparent milk white ink which is added with the ink to slightly reduce the strength (shade) while running on the machine. This can not be used like white ink to alter the strength of the color, but it reduces the color strength to some degree and make the light color ink flow more freely. Some times the printers mix pigments in the tinting medium to make their own shade of inks for some jobs.
25. Titanium dioxide : Called Tio2 this is one of the naturally available mineral used as white pigments to make pure white printing inks and paints. This is also used as white pigment while making other inks. There are two grades of Tio2. They are called Rutile grade produced by chloride process, and the other Anatase grade produced by sulphate process.
26. Transparent ink: All the three or four color process inks used in printing are called transparent inks because they do not conceal the colors that lay below them to show multi color effect. If they conceal the colors that lay below them, then the resultant color will give secondary and tertiary color effect instead of multi color effect.
27. Tri metal plates: The Tri metal plates are meant for Offset Printing and are prepared with Copper for image areas and any other two metals out of Chromium, Nickel, Aluminium or Stainless Steel for non image areas. A metal plate prepared with two other metals by electroforming process is coated with light sensitive material by Deep etch process and exposed through the positive to create the image for Offset printing. Out of the three metals, the copper will form the middle metal. The top layer of the metal will be etched to bare the next metal Copper which is ink receptive. The Copper coating sits on the third metal. The Tri metal plates are meant for long run copies unlike Surface processed Plates or Deep etched Alluminium or zinc plates which can not give as much copies as the Tri metal plate produces.
28. Tung Oil: Tung Oil, also known as China wood oil is used in the ink making process. This acts as pigment carrying vehicle and has excellent drying properties .
29. Three Roll Mill: A machine that is used for fine grinding of the ink in the Ink factories. It consist of three heavy cylindrical rollers or Cylinders that is run in varying speed to grind the ink slurry containing Pigments, Vehicles and Driers to ensure that all the components get well mixed to become usable ink on machine. In the mixture of Pigment-vehicle- drier ,the pigments will have to be crushed well to disperse in the milled ink failing which the inks will not flow on rollers and give even print. This is also called Triple roll mill.

Ink grinding process in three roll mill

30. Two sheet detector: This is nothing but double sheet detector fitted on all the printing machines in the feeder units to ensure that when more than two sheets try to enter into the feed board, the feeder operation will get tripped. The two sheet detector is set in such a manner that on sheet fed machines when two sheets enter the feed board, the feeder will trip. On continuous feeder or stream feeder, since the sheets enter into the feed board one below other by overlap at a specified distance, when more than two sheets try to travel, the feeder will trip.
31. Two or Three Pin Register: This is a special apparatus to register the negatives and positives in multi color separation process. In multi color separation, some times the negatives and positives may be required to be registered with one other to make color corrected negatives or positives in the process called masking method of color correction. In order to ensure that all the negatives and positives lay in perfect register in many such steps, they are processed by first pinning them on a Two or three pin register bars before exposure is made. This will eliminate manually registering the negatives or positives accurately using register marks. Manually registering is a time consuming process and even slight mistake in perfect register will not produce desired result. However by using the Two or three pin register bars the negatives and positives can be perfectly kept in registered position even in dark room while processing the films.The three pin bar is used for positioning the films on the vacuum back of the camera while the two pins are used for contact work on  contact printing down  frames and enlargers.

......Additions to alphabet T to be continued under T/6

Monday, October 29, 2012

Alphabet- T /4

16. Taggant: Taggant is a marker powder which is added with the printing inks to enhance the security feature. Taggants act as a marker which can be read or the presence detected only by a special device which will be specially designed to authenticate them. Taggants are microscopic or nano materials that are uniquely encoded and virtually impossible to duplicate. They will act as human finger prints which can not be duplicated. They are specially formulated chemicals and physically ground to nano particle sizes to prevent duplication. In the documents which are considered to be security documents in nature like Bank Notes, Stamps, and other Brand protected Labels some of the security features used are OVI inks, Holograms, See through and Guilloche designs and water marks etc. They are all visible overt features which the counterfeiters are able to duplicate to some extent. In order to impede such counterfeiting menace, covert (Hidden) features beyond overt (Visible) features became necessary and they are thus provided in the form of Taggants to back up the security. The devices to authenticate them are custom made hand held devices which can authenticate only a particular product for which it has been designed with software inputs. The devices can not be opened to duplicate the inputs because they are sealed in such a fashion that once some one tries to open it, the printed circuit and the parts inside will break and tear off. The Taggants act as covert security features and only a proprietary optic electronic devices and sensors can detect these features. The Taggants are therefore used on the printed labels affixed on the consumable items like spare parts, Pharmaceutical products (labels) and or their cartons as covert ( Invisible) feature to identify the counterfeited products instantly on shops and outlets selling the products. The labels printed with the Taggants can be verified by viewing them through the small hand held detectors which will show Green or Red lights to indicate the genuine product label. Since the Taggants are mostly patented products and specially prepared as customer specific Taggant (which will not be made available to other customers), it will be impossible to manufacture those Taggants as the material required to make the Taggants are difficult to source . Some times the same Taggants will be given to different customers, but their usage will be different pattern and authenticating device will also be adjusted to read the particular points and therefore even when the same Taggant is used by different customers they can not inter mix their products unless the know-how for mixing is given by the seller. 
The Taggants are not readily available across the shops, but only very few firms around the world is in a position to offer them because of patent rights. In addition to brand protection, the Taggants are used for enhancing the security features of Bank notes, stamps, tax stamps etc. Beyond labels, one of the Taggants offered as SmartSure, a patented product, works by authenticating the presence of Taggants in holograms. Upon scanning the hologram, the SmartSure app device connects to a cloud based server where the taggant is authenticated and additional track & trace information is provided (optional). More information can be seen in their site: . Few other firms like Authentix and Micro trace too offer such security features in the form of Taggants for mixing them with inks. Read more under their site: and
There are some more firms who offer such patented Taggants and the above examples are given only for enhancement of knowledge. Authentication of the products by the use of Taggants also comes under the next term Track and Trace both of which are in one way or the other inter connected.
17. Track and trace: This is again a wider term used in the printing industry where in the name of Track and Trace certain applications are offered and also partly connected with the Taggants term. The Track and Trace solution with Taggants are meant for Brand protection, products traceability and to authenticate the printed documents by adding the solutions as security features. The Track and Trace solution also help in the bigger printing presses like security printing units to identity the missing links.
Therefore the Track and Trace solution is offered in two levels. One is to identify the products by their Production location, issued location and batch no etc. The other form of Track and trace is to find out where the printed paper has been lost in the chain of print line. These solutions can be offered only by the specialist firms in the field with warranty and guarantee to function as the entire working system will have to be computerized and used with centralized server.
Let us see by the following example how the Track and Trace solution can function:
Supposing the printing press has three to five divisions that handle the print products in sheets before sending it to bindery unit. The printed sheets are in millions and has to travel through the three main divisions. In case some sheets get lost due to sabotage or machine malfunction and not traced till it is detected by the other department after several days, how to identify from which lot the sheet has been lost, and on which machine it has been lost?
When the sheets are printed in the first stage, every sheet printed will be printed with machine specific bar code mark in the trim area and they get recorded in the central server console through computerized programme. The spoiled sheets with Bar code mark will be read through the reader and accounted in storing unit. In the subsequent divisions when the sheets are printed, they keep on reading the bar code mark while printing and enter them in their data and indicate the missing sheets if any as separate list. The machine spoils from the second division will also get recorded as separate list. At regular periodical-say twice a week, when the data is checked the missing sheets with the specific bar code will be detected. Then the missing barcode no will be compared with those spoils from each sections. From the data, the sheets which have not been printed in the second section onwards can be detected, and the machine location of the previously printed section will also be known along with the shift and time. The data page of the previous section will be opened to check the particular machine on which the said sheets have been printed. The data entry will show the machine on which the sheets were printed. It will also show the time and shift based on which the reasons will be analyzed.
In similar manner in brand protection case with the use of Taggants the counterfeited material can be detected with Track and Trace function. Supposing a high selling product is manufactured at four locations. The batch nos ( which will be unit specific) with unique code will be printed on the Cartons and labels meant for each location. They will be automatically kept recorded in the centralized server via internet connection. They will be dispatched to specific locations across the country. With the field unit periodically checking the cartons at the outlets with a special device which will flash it to the central server, in minutes it will indicate whether the product for distribution in a particular location has been found to be sold in another location whose product code will be different, it can be safely presumed that the product has been smuggled and brought here to evade tax, or a counterfeited product or some unethical business deal is going on with the product. Secondly the non taggant print on the codes will indicate that the product is counterfeited one . The product manufacturer can then immediately institute mass inspection to find out the counterfeited product. 
 ...........Additions to alphabet T to be continued under T/5