Alphabet R /2

8. Reprography : The term Reprography is a wide term that covers various processes including small Offset printing machines like Rota Print, Autolith, Multilith etc (Not bigger machines).  Reprography in real sense means duplication of documents. They include written or printed matter, rare books, Engineering drawings, archives, designs etc and duplicated with processes that are based on or aided by photographic reproduction. Therefore Reprography is reproduction process -Reproducing by Photographic means- to convert the images into readable form, by breaking them into minutest dots, lines , pixels or other formats in real time sizes and images.  Which one of the processes are called Reprographic Processes?

9. Rescreening: Rescreening means, reproducing the halftone image from the already printed book  for reprinting again. Rescreening the halftone is not an easy task and it is a highly skilled job. While re screening the halftone images from the already printed material, if the screening is not proper it may produce Moire effect i.e the image will have checkered pattern or scratchy look.  How then can the halftone be re printed without moire effect?
Every halftone would have been printed with certain screen angle and screen ruling. When the already printed halftone original is again to copied it is done in few ways as given below:

10. Relief Printing : As the name implies, the relief printing means printing with the print matter using relief plates. The printing areas on the plate will be in relief unlike Offset where the printing and non printing areas are in the same plane. The relief printing includes printing processes like Letterpress Printing, Flexographic printing and Numbering where the number wheels have the numbers in relief.
The Intaglio Printing (not the printing process) is also called relief printing because the printed images are in relief and can be felt by passing the fingers over them.
11. Rotary Press : Rotary printing machines are those that print on the  paper through round shaped Cylinder mounted plates and impression Cylinder in contrast to the flat bed machines where the matter to be printed will be mounted on a flat surface and a impression Cylinder rolls over it to cause the print. The Flat bed presses are very slow compared to the Rotary Printing presses. Besides printing on bigger sheets, the Rotary presses are also used for printing on Paper reel. Even though the Flat bed presses also uses the   Cylinder to cause the impression, since the Plate holding bed is on flat surface, this can not be called Rotary. Unless both the Plate or image holding bed and the Impression beds are both in cylindrical shape, the press can not be called Rotary Press.

The Rotary printing machines operate with high speed and therefore are used for printing books, pamphlets, newspapers, magazines, labels, posters, and other items, as well as packaging materials whose print orders are high. The Rotary Printing machines also facilitate printing on both sides in one pass which is called perfecting. Sheet-fed rotary machines use stereotype or electrotype plates, flexible plates made of photo polymers, rubber, zinc and Alluminium plates. Printing of continuous Labels on roll paper has become comfortable and easier on Rotary machines. For multi colour printing work, only Rotary machines are more reliable and give accurate register. With multi colour Printing units on the machines, more no of colors in one pass can be easily printed which is not possible on the Flat bed machines. Platen presses or  Flat bed are used for short run and smaller size  work where only relief printing plates can be used.

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