What is offset printing

Offset printing has been around for more than a century to produce printed materials for organizations and businesses, this printing method produces rich and vivid graphic content and images in a wide range of colors. Offset printing is still applicable and more than 90% of the world's printed materials are produced using this method; Today's offset presses are much more efficient than past models, although the basics remain unchanged.

To get the most out of offset printing services, you need to understand the benefits and decide if the overall cost is worth it.

What is offset printing?

Offset printing, also known as offset lithography, was invented to produce high-quality prints in mass circulation such as magazines, books, and newspapers. The name of this type of printing is offset because the printing ink is not transferred directly to the paper. In offset printing, the computer creates the image on a metal plate, usually made of aluminum, which then transfers ink to rubber pads that roll the ink onto the print bed. In this type of printing, a special design is selected for which film and zinc or plate is prepared, by installing said zinc in offset printing machines and in order to increase the quality of printing output from 5-color simultaneous machines as well as 2-color simultaneous machines. It is used on the woman's back and face.

Printing of all kinds of catalogs, folders, brochures, posters, leaflets, bulletins, books, magazines, sets of office papers (letterheads, envelopes, notes) and other printed items using the most modern offset printing machines in the full-color collection in a completely professional manner Becomes.

How is offset printing done?

Offset printing is a type of printing that transfers the text and photo on the rubber surface of a rotating cylinder and then prints it on the paper with the pressure of another cylinder. The offset printing machine usually has three cylinders, in this type of printing, first what needs to be printed is transferred to a metal plate called zinc, then this plate is sensitized with chemicals so that only the writings and images It takes the printing ink. To perform offset printing, zinc is wrapped around the first cylinder; Its design returns due to the pressure on the rubber cover of the second cylinder. The white paper, which successively wraps around the third cylinder, takes the print design from the rubber cover of the second cylinder. The speed of printing machines in the offset printing method is more than flat (letter) printing.

Among the biggest manufacturers of offset printing machines are Germany's Heidelberg company and Japan's Mitsubishi.

Offset printing is a confrontation between water and compound that takes place on the surface of the plate, which is an aluminum plate, which is called zinc plate in offset printing. The surface of this plate is oxidized by electrochemical methods and turned into aluminum oxide to increase its hardness and chemical resistance. The surface of zinc is covered with polymer materials containing light-sensitive materials of diazonium salts. Zinc is exposed by ultraviolet light or laser to create an image on it, and then it is washed by an alkaline solution to remove the polymer material from the surface of the zinc in the lighted spots. In this way, two areas are created on the zinc surface (hydrophilic areas and lipophilic areas), the image areas on the zinc surface, which is composed of polymer material, are lipophilic and composite absorbent, and the other areas are hydrophilic and moisture absorbent.

In order for there to be a thin layer of water in the non-image areas of the zinc surface to prevent the compound from penetrating, the surface tension of the water entering the zinc surface should be reduced, which is usually done by adding substances such as isopropyl alcohol. take Also, the water in the offset printing machine that covers the non-image parts, which is called the so-called moisturizing solution, must be acidic and its pH should be in the range of 4.8-5.2, using a buffer solution called water medicine and it is added to the moisturizing solution.

Offset printing services:

•   Business card printing

•   Printing of leaflets and advertising sheets

•   Catalog and poster printing

•   Print a complete administrative set such as a letterhead

•   Printing and making envelopes

•   Print greeting cards and postcards

•   Printing and making handmade bags

Advantages of offset printing

Although digital printing has taken over a large portion of the print and advertising market, offset printing is still widely used. And the reasons are as follows:

1-   Print quality

In offset printing, the printed and non-printed elements together form a continuous surface where the printed part repels water but absorbs ink when wet, while the non-printed parts do the opposite. If you plan to print a large number of images in high quality, offset printing is the best choice, you can be sure that with offset printing, there will never be a situation where there is not enough contrast in the images. Clear and accurate color reproduction gives you a professional quality print result, this advantage is especially useful for printing books, brochures, magazines, advertisements, posters, banners and newspapers

2-   Reasonable cost of printing

In the offset printing method, as the number of prints increases, the cost of each printed item decreases, it is popular among applicants due to its low cost for high quality prints compared to rotogravure or photogravure methods.

3-   Adaptability with all kinds of printing materials

With regard to rubber cylinders, offset printing is applicable for all types of printing surfaces, including fabric, leather, metal, paper, plastic, all kinds of banner printing materials, and wood. Offset printing offers you a unique opportunity because you are not limited to just one type of material.

4-   Printing speed

Offset printing machines are known for printing high volume jobs in a short time, they are much faster in delivering large quantities compared to direct printing machines. The fastest known offset printing machine with a production of 10,000 sheets per hour

5-   High durability of offset printing:

Since in offset printing the printing plates are never in direct contact with the media, the results last much longer than direct printing methods. You can achieve over a million prints by using the optimal inks and managing them, which is the cheapest way to produce high quality prints in large quantities

6-   Reducing the consumption of printing ink:

In the offset printing method, the printing machine has complete control over the amount of ink used; A metal blade controls the flow of ink to the cylinder. When the operator adjusts the screws, the space between the blade and the cylinder is modified, this process allows to increase or decrease the amount of ink consumption and change the color density in certain areas of the image.