Why web-offset works so well for newspapers
By Som Nath Sapru
Not too long ago – about two and a half decades – you would perhaps remember the days when letterpress-based rotary presses were used for the production of newspapers. They were messy, labour-oriented and meant a time-consuming process. The scene is still alive and kicking to a large extent in India’s mofussil areas (rural districts and towns), producing medium-sized regional newspapers. Whereas in metros and large towns, Indian newspaper establishments are producing newspapers on high-speed multi-colour web-offset presses with in-line mailroom system
The Indian newspaper industry is worth more than Rs 18300 crore today; it is vibrant and on the growth path. The United States experienced a decline to the tune of 47 per cent in the newspaper industry over the past five years whereas in India, the industry expects 17.9 per cent growth in the coming five years.
Worldwide, the newspaper industry is on a downward trajectory whereas in India it is looking up. How come the Indian newspaper industry is so positive about growth prospects?
The reasons are cost-effective pricing, distribution and overall recycling of used newspapers, all of which contributes to a healthy Indian newspaper industry. This is quite unlike anywhere else in the world. For example, newspapers overseas are costlier compared with Indian newspapers. It is known that the price factor is the main reason for the growth and popularity of newspapers in India, be they national dailies or regional language newspapers. Worldwide, the newspaper industry is on a downward trajectory whereas in India it is on an upward curve.
Shots of the Silverline web machine exhibited at Printpack India in New Delhi this year.
The ever-increasing demand for newspapers in India is the result of literacy growth. We had a literacy rate of 12 per cent at the time of Partition, which grew to 75.8 per cent in 2013. The rise in the number of people able to read and their relative lack of access to online news sources naturally leads to high levels of newspaper readership – a contributory factor to the phenomenal rise in the publishing of regional newspapers.
The print media in India has readily responded to the new changes and challenges with its continued modernisation. It has accepted Information Technology, which has resulted in better coverage, greater speed in news delivery and a cost-effective price. The Indian newspaper industry has graduated from letterpress-based rotary presses to high-speed web-offset presses. It now adapts the latest technology – computer to plate, be it violet or thermal.
Efficiency and speed – Much before web-offset presses arrived in India, offset lithography became the most popular form of commercial printing from the late 1950s, named and accepted as ‘offset printing’. Substantial investment in the larger presses required for offset lithography was needed and had an effect on the shape of the printing industry, leading to fewer and larger printers. The change and acceptance of new technology made increased use of colour printing possible and cost-effective as well. It had previously been much more expensive because of several technical factors. Subsequent improvements in plates, inks and paper have further refined the technology with superior production speeds and plate durability. Today, offset printing is the primary printing technology used all over the world.
Web-offset has entrenched itself in the newspaper industry because of its efficiency and speed and its adaptability to the latest technology and attachments. The consistent high quality of the prints and the volume of prints created at cost-effective prices make even commercial offset printing very efficient and profitable for businesses, especially when you have large print-runs. Constant R&D has resulted in the improved quality of blankets, fountain solutions, plates and inks, so much so that odour-free offset printing ink is the newest technology.
Web-offset refers to the use of paper in rolls – ‘webs’ supplied to the printing press. Web-offset printing is generally used for runs in excess of 25000 impressions or more and comes in handy for newspapers, newspaper inserts/ ads, magazines, catalogues and, of late, text books. Web-fed presses are divided into two general categories: ‘cold-set’ and ‘heat-set’ offset web presses, the difference being how the inks that are used dry. Cold web offset printing dries through absorption into the paper, while heat-set utilises drying lamps or heaters to cure or ‘set’ the inks. Heat-set presses can print on both coated and uncoated papers, while cold-set presses are restricted to uncoated paper stock, such as newsprint. Some cold-set web presses can be fitted with heat dryers, or ultraviolet lamps (for use with UV-curing inks). It is also possible to add a drier to a cold-set press. This enables a newspaper press to print colour pages heat-set and black-and-white pages cold-set.
Web offset presses are beneficial in long-run printing jobs, typically press runs that exceed 25000 impressions. Speed is a determining factor when considering the completion time for press production; some web-offset presses print at speeds of 3000 feet per minute or faster. In addition to the benefits of speed and quick completion, some web presses have the inline ability to cut, perforate, fold and even paste. Economy in time, savings in human resources, speed with consistent quality and overall cost-effectiveness – these are the primary reasons for newspapers being produced on web-offset presses.
How it works : Web-fed offset press prints on a continuous web, of paper fed from a roll and threaded through the press. These days, domestically manufactured web-offset presses, as well, are designed to reach speeds of 35000 to 75000 iph (impressions per hour). Operating speed for optimum production will vary with paper quality, size of product, number of webs and workmanship Web-offset presses are increasingly being controlled from remote consoles, from which the operator can adjust inking, dampening, and circumferential and lateral register; control ink density; and even monitor dot gain.
The web offset press consisting of several sections. The in-feed of the press is where the unprinted rolls of paper are mounted. The delivery is where the final printed material comes out. Going from in-feed to delivery, the elements of a heat-set web offset press are (in order): in-feed, printing units (press), dryer, chill rolls, and delivery (either a folder, sheeter or rewinder). A non-heat-set web press is not designed with a dryer or chill rolls.
A folder delivers folded signatures ready for mailing or for binding with other signatures to form a magazine or a book. A sheeter cuts the web and delivers flat, printed sheets. A rewinder rewinds the printed web back into roll form. A folder produces signatures; a rewinder produces rolls. The bulk of web-offset work involves folding and producing signatures. The ends of the press are referred to as the in-feed and delivery. The sides also have specific designations. One side of the press houses the driveshaft and gears that power the press. This side of the press is called the gear side. The crew always works on the other side because this is where all of the press controls are located, the operator side.
There are three categories of web offset presses in use today:
1. In-line web-offset presses: In-line describes a press with printing units that consist of a single printing couple: an inking system, a dampening system, a plate cylinder, a blanket cylinder and an impression cylinder. The printing units on an in-line press can print only one side of the web at a time. Most business forms are printed on in-line presses. Such presses are generally small and equipped with auxiliary devices such as imprinters, numbering devices, perforators, and punches.
2. Blanket-to-blanket web-offset presses: The blanket-to-blanket press consists of printing couples that are usually stacked in pairs, one on top of the other. The blanket of one couple is next to the blanket of the other couple and the web runs between them. In other words, the presses have no impression cylinders; the blanket cylinder of the top couple acts as the impression cylinder for the bottom couple, and vice versa. Since the units can print both sides of the web at once, a blanket-to-blanket press is perfecting. On a blanket-to-blanket press, the printing units are usually arranged one after the other, an arrangement that offers a great deal of flexibility. With four units, one web can be run and four colours printed on each side. Or the press can be set up so that four webs are run and only one colour printed per side. Anything in between is possible.
3. Common impression web-offset presses: Each printing unit of a common-impression-cylinder (CIC) press has one very large impression cylinder with four or five printing couples arranged like a radial around it. Because of the arrangement of the couples and the size of the impression cylinder, the presses are also called satellite presses.
Heat-set web offset: This subset of web offset printing uses inks which dry by evaporation in a dryer typically positioned just after the printing units. This is typically done on coated papers, where the ink stays largely on the surface, and gives a glossy high contrast print image after the drying. As the paper leaves the dryer too hot for the folding and cutting that are typically downstream procedures, a set of ‘chill rolls’ positioned after the dryer lowers the paper temperature and sets the ink. The speed at which the ink dries is a function of dryer temperature and length of time the paper is exposed to the temperature. The type of printing is typically used for magazines, catalogues, inserts, etc with medium-to-high quality production runs.
Cold-set web offset: This is also a subset of web offset printing, typically used for lower quality print output. It is typical of newspaper production. Here, the ink dries by absorption into the underlying paper. A typical cold-set configuration is often a series of vertically arranged print units and peripherals. As newspapers seek new markets, which often imply higher quality (more gloss, more contrast), they may add a heat-set tower (with a dryer) or use UV (ultraviolet) based inks which ‘cure’ on the surface by polymerisation rather than by evaporation or absorption.
Computer to plate: Computer-to-plate (CTP) is a recent technology that allows the imaging of metal or polyester plates without the use of film. By eliminating the masking, stripping, compositing and traditional plate-making processes, CTP has altered the printing industry, leading to reduced pre-press times, lower costs of labour and improved print quality. Most CTP systems use thermal CTP or violet technologies. Both technologies have the same characteristics in terms of quality and plate durability (longer runs). However, violet CTP systems are cheaper than thermal ones, and thermal CTP systems do not need to be operated under yellow light. Thermal CTP involves the use of thermal lasers to expose and/ or remove areas of coating while the plate is being imaged. This depends on whether the plate is negative or positive working.
The lasers are generally at a wavelength of 830 nanometers, but vary in their energy usage depending on whether they are used to expose or ablate material. Violet CTP lasers have a much lower wavelength, 405–410 nanometers. Violet CTP is based on emulsion tuned to visible light exposure
(The writer has a master’s degree in Print Technology & Management. He served 33 years with the USIS at the American Embassy in New Delhi as chief of publications. During 2005-2011, he headed IPAMA as CEO and was editor of the IPAMA Bulletin. He then moved on to Pramod Engineering, part of the Delhi Press Group, publishers of Caravan, Sarita, Woman’s Era and Alive as general manager.)