Offset lithography (known also as commercial offset printing) is the kind of method in which images on metal plates are transferred to rollers and then to print media. This method was used all over the world since the 20th century. In this type of printing method the paper (print media) doesn’t come into contact with metal plates.
Actually in this type of printing ink and water don’t mix. More specifically, image information is put on metal thin plates, which are dampened by water and ink through rollers. The ink, which is based on oil, adheres to the image and the water to the non-image area. Then, the inked area is transferred to a ‘blanket’ (rubber cylinder) and then onto the paper as it passes around the blanket. This kind of process is actually called offset printing, mainly because the image does not go directly to the paper. Today, many printed brochures, books, various catalogues for businesses, newspapers, magazines, post cards, labels and posters are produced by using this kind of lithographic method. The 4 color offset printing enables small businesses to be able to compete larger firms by providing professional-looking materials.
Advantages of Offset Lithography Over Other Printing Techniques
The main advantage of this type of printing is its high image quality. Actually the process can be used of small to really high-volume jobs. Offset printing produces accurate color, rich and top quality photographs and images, which have sharp details and fine type faces.
Sharpness & Clarity
This type of printing creates smooth and very clear images and contents. In fact, with the traditional way of this type of lithography, the part that presses against the surface or the paper is manufactured out of a soft soft rubber, which can be adjusted to almost any kind of paper or material, unlike any other of relative systems that don’t use flexible metal plates. Moreover, the modern offset printing use also computer-to-plate systems, which increase more the sharpness and the clarity of the images.
The speed of offset lithography is really incredible. In fact, many lithographic presses print on both side of a paper the same time. As a result this decreases the time that something need to be print. Some web press machines of lithography can actually print up to 50,000 sheets within an hour.
Lithographic printers are used in order to produce more effective and advanced printing materials, such as and more precise, such aw art reproduction, direct mail inserts, posters, as well as various greeting cards. The more efficient and high speed web presses are mainly used for medium types of printing materials, such as catalogues, advertising flyers, magazines, books and more. Furthermore, lithographic presses actually work on a wide range of surfaces for printing materials, like leather, metal, plastic, cloth and wood.
Lithography provides lower costs for business who use printing methods. Moreover, these type of printing methods require little maintenance. Even though offset lithography is not a cheaper option for small projects, the overall cost of every page reduces significantly as the quantity of the printed material increases, making lithographic type printing cheaper than digital printing and one of the most cost-effective method that is broadly used today.
Offset printing is a great lithographic technique, that quickly became the standard in photochrome press production. Nearly all papers and books are made through process printing on offset lithography presses.