Over the decades, printers had no option other than offset printing for producing catalogs and magazine printing. But today, we have a powerful alternate printing method called digital printing. There are some striking differences between offset printing and digital printing. Particular projects require alternative sheet-fed printing, offset printing or digital printing based on your specifications.
In other words, in offset printing, the desired print image is burned onto a plate and is then transferred (or offset) from the plate to a rubber blanket, and then to the printing surface. This process is based on the repulsion of oil and water. The image to be printed gets ink from ink rollers, while the non printing area attracts a film of water, keeping the non printing areas ink-free.
Both off-set printing and digital printing technologies have their own advantages. Offset Printing provides high image quality and printing is possible on a wide range of printing surfaces including paper, wood, cloth, metal, leather, rough paper and plastic. The per printed copy cost declines as the quantity goes up. Digital printing will not be able to compete with an offset press if large volumes are to be printed.
If you want a sample of digital printing, simply examine a piece that you print from your inkjet printer at your home or office. Digital printing uses a series of dots printed on top of the paper that form an image. Offset printing is done on large presses that use plates and ink. As your piece is printed on an offset press, the ink bleeds into the paper and bonds with it. Because plates are used, and ink is absorbed by the paper, most printers opine that offset printing provides deeper, richer, fuller color saturation than digital printing. While digital printing has certainly improved over the years, most printing experts would agree that it still has still not reached the quality level of offset printing.
Off-set printing technology is based on ink and water that do not mix. To keep ink away from
the areas of the plate not engraved, the plate is flushed with water. Because water and ink repel each other, the ink adhered only to the engraved area of the plate. A plate is required to carry the image. In earlier lithography, the plate containing the image contacted the sheet directly, whereas in today's offset printing the image is transferred from the inked plate to a rubber blanket that contacts the sheet. The image offsets from the plate to the blanket, then offsets again from the blanket to the paper.
the areas of the plate not engraved, the plate is flushed with water. Because water and ink repel each other, the ink adhered only to the engraved area of the plate. A plate is required to carry the image. In earlier lithography, the plate containing the image contacted the sheet directly, whereas in today's offset printing the image is transferred from the inked plate to a rubber blanket that contacts the sheet. The image offsets from the plate to the blanket, then offsets again from the blanket to the paper.In other words, in offset printing, the desired print image is burned onto a plate and is then transferred (or offset) from the plate to a rubber blanket, and then to the printing surface. This process is based on the repulsion of oil and water. The image to be printed gets ink from ink rollers, while the non printing area attracts a film of water, keeping the non printing areas ink-free.
Digital printing, simply stated, is high-speed laser printing. Laser printing uses a single source of concentrated light to expose the image on to photosensitive material available on a drum or belt. Electrically charged toner is attracted to the image on the drum or belt that has an opposite charge. Finally, the toner particles are transferred to the paper and fused to it with heat and/or pressure. The growth of digital printing technology has brought technical advancements and consequently many exciting possibilities to today's commercial printing. Digital printing eliminates many of the mechanical steps required for conventional printing, including making films and color proofs, manually stripping the pieces together and making plates.
Both off-set printing and digital printing technologies have their own advantages. Offset Printing provides high image quality and printing is possible on a wide range of printing surfaces including paper, wood, cloth, metal, leather, rough paper and plastic. The per printed copy cost declines as the quantity goes up. Digital printing will not be able to compete with an offset press if large volumes are to be printed.
With digital printing, the turnaround time is very fast. The quality of print is consistently good from the first to the last copy, due to not having to balance ink and water during press run. While the unit cost of each piece may be higher than with offset printing, when setup costs are included digital printing provides lower per unit costs for very small print runs.
Variable Data Printing is a unique feature of digital printing. Using information from a database or external file, text and graphics can be changed on each piece without stopping or slowing down the printing process. For example, personalized letters can be printed with a different name and address on each letter. This is extremely useful as variable data printing is used primarily for direct marketing, customer relationship development and advertising.
Offset printing may be uneconomical for short runs as per copy cost will be high. But as volumes increase, the unit cost will steadily climb down. Short runs can be much more cost effective with digital printing; while larger quantities are likely to have a lower unit cost with offset printing. As regards printing medium, if you want to print on special paper, finish or unusual printing surface, or unique size, offset printing offers the maximum flexibility – although the options are gradually enlarging for digital.
Digital presses are capable of four-color process printing. But if your requirement is only black ink or one or two ink colors, offset printing may prove more cost-effective. But if you need four-color printing, digital may offer advantages in lower up-front costs. As regards proofing, digital has the distinct advantage of offering accurate proofs since an actual sample of the printed piece is readily available. Accurate color proofing for offset printing will no doubt be expensive. Again, talking of customization, digital printing offers the most affordable way to customize sales promotional materials, direct mail, letters, etc.
As technology is rapidly advancing, the quality and versatility of digital printing is also bound to improve. Technology advancements have also made it easier for more and more businesses to enter the printing industry. Whereas good digital printers cost only a few thousands dollars, good offset printing presses may cost a few million dollars. For those business houses interested in obtaining the best possible image at all times, it is important to evaluate which printing process will bring better result.Let's compare the two processes briefly.
If you want a sample of digital printing, simply examine a piece that you print from your inkjet printer at your home or office. Digital printing uses a series of dots printed on top of the paper that form an image. Offset printing is done on large presses that use plates and ink. As your piece is printed on an offset press, the ink bleeds into the paper and bonds with it. Because plates are used, and ink is absorbed by the paper, most printers opine that offset printing provides deeper, richer, fuller color saturation than digital printing. While digital printing has certainly improved over the years, most printing experts would agree that it still has still not reached the quality level of offset printing.A professional printer is obviously expected to have the right kind of equipments to meet the printing requirements of his customers Years ago, it was adequate for a printer to own offset printing presses. But today, due to business compulsions, he is also required to have digital printing equipment and high-speed copiers. Even though digital printing technology has improved vastly over the past decade, offset printing is still the choice if someone wants superior image quality. This is because an offset press plate can be imaged to a higher resolution than a digital printing image carrier. Ink film will adhere more exactly to a fine line or small dot than a particle of toner, whose size may be larger than the line or dot it is adhering to. For business printing, the choice between Off-set and digital depends on a variety of factors such as -production cost, amount of time needed to produce the job, the quantity required, the kind of paper that must be used and color fidelity.