Excursion on offset printing: basic varieties

In order to classify offset printing, two main categories are used, with their own subsections. Offset printing is distinguished by the presence or absence in the production process of wetting (in more detail below) and by the type of media used in the process.

In terms of moistening, the offset is distinguished:

• traditional;
• dry.

In terms of carriers are distinguished:

• Roll;
• sheet;
• Narrow format;
• Widescreen;
• Full-length.

We will discuss in more detail each of these varieties and describe the features of each variant of offset printing.

Traditional offset or offset with moistening

This option for creating printed products is considered classic. Offset with moisture for this period is the most common in print shops around the world. Although in the future, other printing technologies may well become more common, because in this area, there are always some improvements.

For printing, special printing plates are used, which are filled with blank and printed elements. Simply put, where there is a letter or sign on the final product, this symbol is placed on the printed form, and where there is a space or free space to be made, white elements are placed.

Printed items attract dyes, and whites attract water. This process is automated and uses special printed forms that are produced by specialized enterprises. Such forms are the most common and have a lower cost compared to forms for dry offset.

Dry offset

A relatively new technology created by Toray Industries (Japan) in 1982. Technologically, the process of dry offset is a bit more complicated, although in a certain sense it facilitates the tasks of the printing workers. In particular, the printing process does not require control over the ratio of water and paint in the moisturizing solution.

The whitespace here is highlighted by silicone inserts on the printed form. Such forms are less common, but the main difficulty is the search and acquisition of dyes for dry offset. These dyes are manufactured according to a laborious recipe and a limited number of manufacturers.

Now let's proceed to the classification of offset printing on the media used. Under the carrier, here is meant the material on which the final image from the printed form is applied.

Roll offset

The carrier here is the so-called roll, that is, a roll of rather large paper. First, the paper passes under the printed form in a roll and only then cut into a certain size and folded.

Rolling machines, as a rule, are installed only at large printers. Such equipment is very expensive and therefore is cost-effective only for large companies. For the most part, only large runs are performed on rolls.

Sheet offset

As it is not difficult to understand, here carriers are separate sheets. There is a pair of cylinders on which the printing plate is located, there each separate sheet is transmitted by means of suction cups. After laminating, an impression with one or another image appears.

Ideally, immediately after the first rolling a full color impression appears, but in reality many printing devices do not have the necessary number of sections. Therefore, sheets need to be rolled through the cylinders multiple times in order to obtain the desired image. In this case, each time it is required to align the media in order to print in accordance with the template.

In addition, there are equipment with several printing units. Such units are the best option for creating a multi-colored image. Rolling sequentially through several sections, the carrier acquires the appropriate colors on the desired sections of the web.

This variety is the most popular and is used to create a wide variety of printing products:

• Creation of booklets for advertising and marketing;
• Replication of periodicals;
• Printing of labels;
• The production of forms;
• Preparation of annual reports;
• Poster printing (http://www.giprint.ru/plakaty/);
• Packaging degassing.

There are other types of printed products, which are often produced by this way of offset.

Narrow Format Offset

For these devices, a canvas is used which has a transverse dimension from half a meter to 60 centimeters. For the most part, narrow-format offset, sometimes called half, is used to create products for commercial printing of high quality.

Wide-format offset

The canvas here has a significant size in diameter, which is from 135 to 190 centimeters. The work is mostly super-large, the range of manufactured products is very diverse from creating maps to large-circulation magazines and newspapers.

Full-size offset

The cloth in the cross-section has a size from 84 centimeters to one meter. Accordingly, it is quite possible to call this type of offset medium format. The range of products is diverse, here can be produced:

• Books;
• periodicals;
• packaging;
• Catalogs;
• Magazines.

It should be noted the use of a method that allows you to improve the performance of equipment when creating logs. In the printing process, two rolls are simultaneously sealed. Further, these rolls are connected by means of a folding machine and are eventually compiled for the journal in the required sequence.

Http://www.giprint.ru/technology/ofsetnaya-pechat/