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'

Monday, September 3, 2012

Alphabet- C


1. Caliper: It is an instrument to Measure the thickness of the paper which is normally expressed in units called micron (1 mm equals 1000 microns). Also available is a tabletop model(caliper) with which the thickness of the paper is measured in several areas to work out the average thickness of the paper. Some units measure the thickness using hand held micrometers. Also see under Basic weight of paper in B/2.
2. Coated Paper: Some of the papers are coated with some material to give gloss and smoothness to their surfaces. Paper coating is done with such material while manufacturing the paper. The coating material is something like clay and other similar substances that improves reflectivity and ink holdout. Mills produce coated paper in categories like cast, gloss, dull and matte. Example of coated paper includes Art paper used for the production of the magazines and PVA, melamine or gelatin sized paper used in the Currency note printing units. Please note that coated paper is different from that of varnish coated paper which is used in packaging industries. The varnish coating is done on printing machines after the paper is manufactured in the paper mills. If however large scale order is placed, the paper mills themselves arrange for varnishing before the reel is wound.
3. Collate: A finishing term which refers to the process of gathering or collecting the printed sheets in the correct sequence or finished order for further processing like binding into a book form. Each set of printed sheet is kept on a table in sequential order and one set from each is gathered in their sequence to make a complete book. 
4. Color Balance: A term which means the proper ratio of cyan, yellow, magenta and black ink to produce the proper color to match the original which is reproduced in the print form. During colour proofing stage appropriate colour / shade to match the original, the extent to which the ink density be allowed on the machines etc are finalized with test prints so that when the same shade of ink is used on the press the resultant image comes as close as possible to the color proof. Such an exercise is called colour balancing. Color proofs are valuable guides, but due to the inherent differences between color proofing techniques and printing itself, proofs may not match the printed sheet to some extent. 

5. C1S: Signifying that the stock has been coated on one side only.
6. C2S: Signifying that the stock has been coated on both the sides.
7. Color Bars: A strip of color patch – incorporated in the printing plate or block- is allowed to get printed on the edge of the sheets one after the other in a row while printing on web presses. Such colour patches known as Colour bar is used to validate color accuracy. Such colour bars are in different shapes such as a circle divided with as many colors printed each division representing a particular colour, or a simple rectangle in smaller size placed in a row each rectangle representing one specific colour. You can also see such colour bars printed on the edges of the newspapers or magazines. 

8. Casting off: Casting off is an exercise to estimate in advance the lines required to be composed, no of pages to be set when printed in a particular size and style of font. The calculation will also take into account the area per page to be printed while casting off so that the exercise remains to near perfection. Casting off is essential to estimate the cost of a given job where the manuscript runs to several pages. The casting off if carefully and properly done will also show how much the manuscript will make if a different set of font size or styles are used. This is basically a typographic calculation. However casting off the hand written manuscript is more difficult. In short this means estimate how many lines or pages of type will be set from (a given amount of copy)
Example: Supposing a manuscript contains approximately 7600 words, how much page it will work out if composed with 12 pt Ariel Unicode font in A 4 page with ½’’ margin on all sides.
Every press has some sample sheets containing few lines of each composed matter in different fonts and sizes. Keeping them as guide you can calculate thus for the main pages that contain text material. The pages for introduction, index, contents, glossary etc are to be added separately with the calculated main pages depending on the nature of layout proposed for such pages. 

9. Casting up : This term refers to calculating the space that a particular font will take up when printed, and using that figure to estimate the number of pages the final book will have. In short casting up is to find the amount of mechanical setting required .
10. Calligraphy : Fine or ornamental handwriting related to writing in a particular style. Calligraphic type fonts are available and are used for printing invitations, specially wedding invitations, modern greetings, various letters of events, logo designs, letterheads etc. In the past only hand written format was used and copied till such time such type faces were developed.
Few examples of Calligraphy scripts include the following:

11. Color Correction: Term meant for photographically adjusting the densities of the negatives or positives before preparing the plates for printing. This is resorted to improve color rendition, for example by photographic masking techniques, dot etching, retouching, and electronic scanning. There are various types of colour correction techniques coupled with special types of films offered by photographic companies. In the past the negatives and positives were hand corrected to adjust the varying densities by an expert artist using artist brushes and cotton and with certain chemicals. They can manually study the areas to reduce the densities or increase the tonal areas before final halftone negatives or positives were prepared for making the plates for printing. This is done to increase or decrease the particular colour densities in the process department so that the print quality will be enhanced. The color correction was also done by the use of different colored filters while processing color separated negatives or positives. In color separation process , the originals are colour separated using three different colour filters in front of the lens on the process camera. The images are formed depending on the amount of reflected light from the original. Those negatives were used for preparing the plates with which the printing is carried out. Due to colour deficiencies in the process inks the resultant prints may not match the original. In such a case some of the colour separated negatives /positives must be adjusted to counter balance the colours in the manner either manually as described above or by other auto process equipments. Re-adjusting the densities on the negative / positive is called Color Correction. While the color correction can also be carried out to some extent, say 10-20% by changing the shades of the process inks on the printing machines , only photographic color correction lends the job a perfect finish. With the latest state-of-the-art scanning technology one can deliver perfect colour corrected negatives/positives to prepare plates or for use even in C T Ps (Computer-To-Plate) within hours. With special software available in the market, once the original art work is photographically scanned, colour corrections can be made and imperfections can be eliminated without resorting to hand corrections. 

 
12. Calorimeter: A calorimeter is a light-sensitive instrument that measures how much color is absorbed by an object or substance. This is necessary for colour management system. It determines color based on the red, blue, and green components of light absorbed by the object or sample and the extent to which they are reflected back. While the application is vast, it is suffice if the learners understand that in the printing industry this application include checking the electronic components and quality of pulp paper and measuring the quality of printing ink and the color profile of a computer monitor change. The changes make the monitor present a warped view of reproduced images.
However the calorimeter plays vital role while feeding inputs in the instruments and apparatus by which some of the covert (hidden) security features in the prints are authenticated. Most of the authenticating equipments and apparatus works out the result by the wavelengths and intensity of the light reflected back from the print medium as the pigments in the ink absorb light at different wavelengths.
13. Collotype : This printing process invented in the year 1856 though once a popular process in printing is almost extinct now. Collotype printing which is 19th century printing process is a photo mechanical printing process that can reproduce color images without the use of halftone screens. Collotype is considered to be the finest technique for the reproduction of fine art; however, because of the relatively long time that it takes to produce a collotype print and the expense of the process it is slowly disappearing from the printing world, even though some of the firms in Europe still continue to use this process to produce works of art in various colors. Very old images of Paintings, sculpture, frescoes, mosaics etc modern art, vintages and greeting cards are still printed through this process in by the centuries old presses as fancy item. However for academic interest the printer should know the process. By this process the continuous tone images are excellently reproduced than the present halftone images.
In the process, the plate is coated with a light-sensitive gelatin solution and exposed to light through a photographic negative. The gelatin is hardened in exposed areas and is then soaked in glycerin, which is absorbed most in the non-hardened areas. When exposed to high humidity, these areas absorb moisture and repel the greasy ink. The hardened areas accept the ink, and the plate can be used to print a few thousand copies of the positive image.
For academic interest few prints made on Collotype is reproduced below:

Photo Courtesy: http://www.collotypeprints.com/

14.Comb Binding: A common binding technique which uses a plastic spiral like material to bind a document of loose sheets. This method of binding is commonly used for binding Seminar material, Thesis, Annual Reports, Project Reports and many such small quantity of material. Instead of wire stitching the loose sheets and then putting up the cover material, the spiral binding called comb binding is adapted to bind the books. The comb bound book pages can be fully opened up to the back edge. The combs comes in different colors and widths to accommodate small and large numbers of pages. Documents can be bound with or without covers. The advantage of this kind of binding is that it allows books to lay flat when opened. First the loose sheets are gathered together, trimmed to size and edges punched with special drilling machine containing a series of drills of uniform size and thickness. Once the sheets are punched at pre determined back edge of the book , they are kept together in tight position and the spiral plastic inserted into the holes and rotated till the inserted edge reaches the top edge. The excess spiral is then scissor trimmed. 


............Additions to alphabet C to be continued under C/2  

3 comments:

  1. Vaijinath Garad vaijinath.g@reproindialtd.com

    Dear Sir,
    This is really great thing, started by you Sir, it will help students-teachers of printing, printers-print buyers and all other peoples related with printing industry, to clear the terms and concepts in printing.
    I really appreciate the efforts taken for this & must say thanks. a lot….! Behalf of all readers of your blog I will regularly follow you…. And I will pray to God for your this great work and your health.
    I am sorry… it’s too late to reply your mail.
    Thanking you,
    Vaijinath

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    2. I have reproduced above the mail received by me.
      Thanks Vaijinath for your comments.

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