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'

Wednesday, September 12, 2012

Alphabet-E



1. Emboss : Read under debossing.
2. Emulsion : Light-sensitive chemicals like silver halide and similar silver salts coated on papers, films, printing plates and stencils which when affected by light rays becomes black. Silver halide grains are irregularly shaped crystals like pebbles, or grains of sand and is a very useful material for photographic emulsions because it turns black when exposed to light. The special coated halides remain dry on the surface on which they are coated. The coated material with gelatin as adherent (emulsion) will be like a crystal of varying sizes. The size of the crystals determine the sensitivity of the film, contrast and resolution rendered by them after exposure to light. The gelatin supports, separates, and protects the crystals. The typical emulsion is approximately 10 micron thick. 

The emulsion lies as a latent image ( invisible to naked eye) till they are treated with special chemicals called developer to convert them to black image visible to naked eye. While in black-and-white photographic film there is usually one layer of silver salts (emulsion), in the case of panchromatic films (colour), the crystals are formed with three different layers (emulsion). In the case of black and white films when the exposed grains are developed, the silver salts are converted to metallic silver, which blocks light and appears as the black part of the film processed. In the case of colour films the three layers in the colour film will be sensitive to one wavelength of the emitted light rays and when exposed, the silver salts are converted to metallic silver, just as with black-and-white film, but the chemicals known as developer solution convert the emulsions to colored dyes. In short the emulsion is considered to be the heart of film. It is the part of the film that records the image by physically reacting to light that reflects from the original being processed.
3. Etching: Etching is a process by which certain chemicals with acids are used to remove- etch away- the unexposed areas of a photographically processed metal plate. The metal plates include metals such as Aluminum, Zinc, Steel, Copper and Bronze etc. The unexposed portions of the plates are bitten into the metal plate through the use of acid and this action is called the etching. Chemicals mixed with acid is applied in the process of etching. The longer the plate is exposed to the acid, the deeper the bite they will cause. Different depths are achieved by covering some lines with acid-impervious coating (stop-out) and continuing the etching a second (or third) time whenever the metal blocks for Letterpress printing is made . The illustration will show how the process of etching is used in three basic techniques of image making. 


4. Electro photographic process: This is nothing but Xerox process where in the Selenium coated plates are used for copying the originals from the plates of which the copies are taken. His process works on the corona discharge process. In short this is printing process that uses principles of electricity and electrically charged particles to create images.
5. End Sheet or End Paper : This is again a bindery term of the sheet that binds the inside pages of a bound book to its cover. In short this is holding together of the main printed material in book form with its cover. Normally the end papers will be thicker than the main printed sheets and are pasted on top of the printed book as first and last folded sheet so that one leaf will get pasted with the cover and the other will remain as empty page when the book is opened. In other words the end paper serves as a protective sheet for the title page or other leaves that follow it including the last sheet of the book. See illustration below to understand it better. 


6. Engraving : This term need not be confused with etching. It is an art whereby the images required to be printed are first engraved i.e cut into the surface of a metal. The engraving is done either by manual process using special tools or by automatic machines. An expert engraver can engrave various shades of the images on to a metal plate by his skill. As for printing, the engraving is an important process to make Intaglio plates, especially for security printing purposes. 

7. Effluent: Effluent is the liquid discharge or waste products of the paper making process, or printing process usually including a small amount of suspend solids, contaminated water, dissolved chemicals, inks etc. Effluent is usually discharged into rivers or if the effluent generated is of huge volume, a separate plant is set up to treat the waste to environmental regulations and then discharge them in a suitable manner. Stricter law governs the effluent discharge.
8. Easter base: This is a substrate used for the production of films and is a proprietary product of Kodak film company. This substrate has high dimensional stability.
9. Estimate : This is a technical term meant for calculation of various factors. Including the cost. By proper estimation, the requirements of various material to complete the work or book of ‘n’ no of pages, approximate time that may take to complete the work etc can be calculated. One of the first thing an prospective buyer wants to know is what the cost would be. The estimates should be near accurate, lest, the customer will not be satisfied and go away or the printer will incur loss due to wrong calculation.
10. Estimator : The individual who works out the cost factor for pricing or estimating the time frame for each work related to delivery date of the product produced. Accuracy of estimation is possible only when an estimator knows exactly what operations are involved in a job and how long a process normally takes for completion. An estimator need not be an expert in arithmetic, but accuracy and orderliness are necessary coupled with speed in estimation. Most of the running press units have standard rates for calculation of a fixed variety of job like printing of letterheads, small booklets, visiting cards, greeting cards, single page pamphlets etc on ‘n’ size and quality of paper with ‘n’ no of sheets in ‘n’ no of colors. However for work of huge quantity and size, and multi colour work, the estimate will have to be carefully worked out. The model sheet of estimating a work is given in E/2

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