Offset printing has come a long way from when it was first introduced. Since then, so many innovations had been made to make offset printing what it is today. This resource page was made to provide you useful information about how offset printing works. Know more about its history, the different printing processes, product benefits, uses, the types of offset presses and other relevant details about offset printing.
Out of all the printing processes, offset and digital are the most common. Large companies, however, lean toward using offset presses for commercial printing because these tend to be more cost-efficient in bulk quantities. The process involves transferring an inked image from a plate to a rubber mat and then onto paper, hence the name offset printing.
Offset printing was discovered after a production error. The first person to use an offset press to print on paper is an American named Ira Washington Rubel. He came upon offset printing in 1903 while operating a lithographic press, typically used to reproduce artwork through printing plates made of limestone and rubber. He forgot to insert paper between the plates, causing the image to be transferred onto the rubber plate. Realizing his mistake, he made adjustments and redid the process. Rubel later found that the rubber plate left a sharper image than the limestone. He soon decided to create a machine that will use that same printing process.
Traditional and Modern Offset Printing Process
After Rubel’s discovery, Charles and Albert Harris, brothers who owned the Harris Automatic Press Company, decided to create a press of their own and incorporated Rubel’s design. They created a machine modeled after a rotary letter press. The brother’s invention is the model by which modern offset presses today were patterned after, although slightly altered over time because of the different contemporary variations brought by technology.
Offset printing uses the same process as that in lithography. Text and images are transferred onto the paper using a lithography technique based on the repellency between water and oil. This process helps prevent ink smudges.
Computer-to-plate (CTP) is a very useful process in modern printing. Through a desktop publishing application, an image is created and outputted on printing plates. CTP provides quality produced prints with accuracy of getting the desired color from the CMYK-generated computer screen.
Plates used in offset printing are faster and more affordable to produce, making CTP an ideal production process for bulk printing. It also helps in producing high-quality products through precise printing registration and image-to-edge repeatability.
The modern offset press is equipped with metal plates, rubber blankets, offset and plate cylinders, and ink rollers. How does it work? The ink from the ink rollers is transferred to the metal plate then onto the rubber plate. The image on the rubber plate is directly pressed onto the paper. Once the print comes out of the press, it goes through an oven to dry. After it goes through the oven, the paper is pressed by chill rollers to prevent the ink from smudging.
A regular offset press can hold up to 2,000 pounds of paper. Offset presses can also produce large quantity of prints at great speed. Both these facts make offset printing a viable solution for high-quantity printing.
a. Perfecting Press. This type of printer can print on both sides. Perfecting press is ideal for producing prints with back-to-back designs like postcards, brochures, menus and other similar materials produced in large quantities.
b. Sheet-fed Offset. Not all offset presses use rolled papers for printing. Sheet-fed offset presses print one sheet at a time. Feeding papers one by one ensures that all the text and images are positioned proportionally on every page. This is ideal for small- to medium-sized printing jobs.
c. Web Offset. Unlike a sheet-fed offset, this type of printer uses rolls of paper and produces prints at high speed. Web offset press works best for long-run printing jobs. It can make 10 to 20 thousand impressions, making it ideal for low-cost production.
d. Heatset Web Offset. A heatset offset press is the ideal machine to use for printing glossy or coated papers. It is a type of web offset that uses inks that are dryer-friendly. The ink stays on the surface of the prints while drying, resulting in glossy prints. It is ideal for producing mid- to high-volume prints like catalogs, inserts and magazines.
e. Coldset Web Offset. Newspapers are mostly printed through a coldest web offset press. This offset has two types of ink drying methods—one absorbs the ink into the underlying paper and the other uses UV-based inks that “cure” on the paper surface after printing. This printing method can produce a large quantity of printed materials.
f. Blanket-to-blanket. Most offset presses have three or more cylinders but blanket-to-blanket printers only have two. Like perfecting printers, this press can print on both sides at the same time. There is no impression cylinder since the rolls serve as impression rolls to each other.
a. Letterset. This ink type is called “dry offset” because no water is involved in the printing process. These are normally used for letterpress printing. The inks are transferred from a printing plate to an offset blanket before being pressed onto the substrate. The absence of water results to an unlimited variety of inks produced when printing on paper.
b. Waterless. These are designed to be used in waterless lithography, an offset printing method that uses silicone compounds to prevent the inks from getting into the non-image areas of your plate. Waterless printing is prone to toning, known as the transfer of inks to a non-image area of the plate, and is caused by the rise of the ink’s temperature. Therefore, waterless inks help minimize toning as these are resistant to the temperature changes undergone by the inks during the printing process.
c. Ink/water balance. It is very important for the ink and water to be balanced and proportioned to each other during offset printing. If the ink and water aren’t mixed properly, the ink may not dry on the substrate, making the faultily printed product to be unfit for delivery.
Benefits of Offset Printing
Many businesses ordering printed products in bulk rely on offset printing for a number of reasons. In fact, offset printing is ideal for commercial printing today.
With modern computer-to-plate printing technology available for offset printing, you can get your prints at a much faster printing turnaround time. Also, offset printing produces consistent, high-quality images by undergoing low production costs. This can be explained by the use of plates to transfer the design to a substrate. Since all pieces of an order will make use of the same plates for printing, the price per piece is much affordable. This is more cost-efficient compared to digital printing, which prints your orders using the same resources from start to finish. As a result, the price per quantity for bulk print runs is much more expensive. Therefore, all pieces produced using offset presses will be printed in excellent quality, even for orders beyond a thousand quantities, at affordable prices!
Source:Digital vs. Offset Printing
Offset Printing: Products and Uses
These large marketing tools are commonly used as POP (point-of-purchase) displays and print ads to promote products and services. There is a high demand for high-volume printing of posters; quantities of at least 250 posters are commonly printed through an offset press.
Almost all businesses, from small- to large-scale enterprises, are using brochures to inform people about their company, products or services. These foldable print materials ordered in bulk are usually printed in large quantities and handed out to customers.
Direct marketing still works well today, which still makes postcards effective tools for reaching out to your target market. These are commonly produced in large quantities and are sent out to prospective clients and customers who signed up for the mailing list. Postcards are printed using offset presses to accommodate designs requiring back-to-back printing.
4. Business cards. If you want to give out your contact details to potential business partners and clients, designing your business cards and having these printed using offset presses can help advertise your business to people who matter. Unlike other print products, these cards come in small sizes, which make them perfect to be handed out and easily kept in the recipients’ pockets or wallets. Business cards produced in 250 quantities using an offset press or more are affordable materials to help boost your business.
5. Folders. These medium-sized print materials are used to compile documents or paperwork for business or promotional purposes. Through the offset printing process, folders are produced in high quality, regardless of the number of prints.
6. Flyers. Most flyers are printed on both sides containing information about the product or service. Since these are handed out in places with high pedestrian traffic, these promotional tools are ideally printed at 250 pieces and are produced using offset printers. The cost is cheaper while providing high-quality output.
• Printing companies. Since these companies cater to a variety of businesses with different printing needs, it’s a must for every printing company producing large printing quantities to have offset presses. The production process is affordable and cost-effective not only for the company, since the printers make use of fewer resources for large quantity orders, but also for the clients.
• Medium- to large-scale businesses. Businesses using print materials for advertising purposes and covers a large number of markets will benefit from offset printing. With a low budget, they can make bulk prints in excellent quality. Also, the different print materials available to be produced using offset presses help businesses to select which of the materials fits into their marketing strategies.
• Campaign advocates. Election seasons, product launches, recruitment and business openings — these advocate groups need to promote their cause using print materials in large quantities. Postcards, flyers, posters and brochures are the most popular marketing tools given out to people in support of the advocates’ campaigns. Hence, it is important for advocate groups to get their orders printed using offset presses to avail of high-quality print materials of their liking.
Offset printing is one of the best ways to produce the different print products in numerous quantities while maintaining the quality of each piece from start to finish. Not to mention, this printing type is reliable, fast and affordable! For owners of small businesses and alike, offset printing is the ideal process to print your promotional materials.
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