Conventional and rotary offset printing

Rotary offset printing

An example of rotary offset printing is newspapers as they are printed from a roll of paper, another example is label flexography as the unprinted label comes directly from a roll.

Rotary offset advantages and disadvantages

The advantages offered by the system are:

• As for printing plates, they are cheap, quick to produce, and easy to replace or adjust.
• It is economical for short and medium term operation.
• Compared to flexo and gravure printing, fine lines are printed in halftone images and bright spots are preserved.
• Supports very fine halftone screens.
• Print on all types of media.
• Provides low-gain midtones and excellent sound range.
• You can make some color adjustments while printing.

His weaknesses are:

• Oil-based inks dry very slowly, although this can be fixed with UV or EB curing inks.
• It does not produce a solid color surface like flexo or gravure printing, and input is very low, which can be compensated for by adding an additional flexo module before offset printing. The modularity of Rotatek machines offers this and many other options.
• The need for oily inks and moistening of the substrate can complicate printing. The solution consists of a water cooling system and a compound solution pumping system. Rotatek offset presses include it to ensure the correct ink temperature, pH and balance.
• The initial investment of offset printing equipment is higher than that of flexographic printing, but since the consumption of ink and printing plate is much lower, it has been worth it.

Conventional offset printing

Conventional offset printing is paper cut to size on the machine to print sheet after sheet, if you have an 8 letter offset press it is necessary to cut all the sheets of paper to this size with the guillotine so there is no waste.

Depending on the size and number of print heads, the machines can print whatever you want.

You need to know the requirements of each print since you know how much paper, grammage, finishes and how many colors you are going to send to each job to be printed and it is clear which offset machine they will make to avoid any errors.

Since you know much more about rotary offset, we also invite you to learn about inks for offset printing.