Offset printing- the engine that set off the printing process

Offset printing, was, for several decades, the only way to print a color image on paper. Currently there are several methods of printing color images. For large print runs, offset printing still remains the best option in terms of price and quality.

Offset printing process involves the transfer of liquid ink from the printing plate on an intermediate surface (such as a rubber cylinder) and then to the media (paper), a complex process done of course with the help of printing machines designed only for this purpose.

The process as a whole, has its own advantages and disadvantages as any other. For offset printing, the preparation for printing lasts longer, because it requires additional operations such as: making films and plates, cleaning and calibration of the press. As mentioned before, the method is meant for medium and large print runs, the advantage being based on a very high processing speed of the printing machine ,which can print up to 10,000 sheets of paper per hour.

Also being the most common printing method, in terms of image quality, the result is a clear and life-like image in natural colours, thus it is perfect for large printing format. It’s good to know that ,in terms of chromatic, images are directly influenced by the characteristics of the support type (whiteness, glossy, matte or metallic surface etc.). The more absorbent the support , the more decreases the contrast and brightness of the printed image. The printing itself is influenced by the color of the paper or paperboard.

Related to ink, offset printing machines are easily to use with spot colours and Pantone. Besides conventional inks (CMYK and Pantone) there are colors with special properties (pearl, scrape, or un-absorbent or thermo-sensitive environments that react to rubbing with a metal), which can be used for special printing.

Other advantage of offset printing is the possibility to adjust the amount of ink on the fountain roller with screw keys. By adjusting the screws, the gap between the blade and the fountain roller is modified, leading to an increasing or decreasing amount of ink applied to the roller in certain areas.Thus the colour’s density in the respective area of the image is altered.

Every printing technology has its own identifying marks, so does offset printing and its machines. There are basically two types of presses: sheet-fed and web – fed. Sheet-fed means that individual sheets of paper or paperboard are being fed into the press with a suction bar that lifts and drops each sheet onto place and is used mainly for printing short-run magazines, brochures, letter headings, and general commercial printing.

Web-fed refers to the use of rolls (or “webs”) of paper supplied to the printing press and is generally used for runs in excess of thousands impressions (examples: newspapers, newspaper inserts/ads, magazines, direct mail, catalogs, and books). You have not deciced which type suits you best? Allow somebody to give you a hand, as the market offer innumerable solutions, the best advice awaits on http://www.allforprintmarket.com/2-printing-machines/.