What is Offset Printing?

What is Offset Printing?

In today’s printing world, there are two main methods of printing: offset and digital. If you go to your local print shop, they will likely ask what type of printing you want for your job. For now, we’re going to focus on offset printing, which is a widely used commercial printing technique that produces high quality and consistent printed materials. Offset printing is typically used for larger printing jobs that consist of 1,000 or more pieces of printed material.

Here at iTek, your local Concord, NC printing company, we believe in education our customers about the different types of printing that we employ. Here’s a quick overview of how offset printing works.  

Step One: Pre-Press Production

Before the job can be printed, the document has to be converted into film and plates. When it comes to creating film negatives from digital files, think of the process as being similar to that of photography. A precise amount of light is allowed to pass through the film negatives to expose the printing plate. Then, a chemical reaction occurs that allows the ink-receptive coating to be activated. This reaction is what allows the transfer of the image from the negative to the plate.

There are different types of plates, which vary in quality (paper produces a lower-quality product, while aluminum is more costly but produces a much more high-quality print). Each primary color has its own separate plate, and only these four colors are used.

Step Two: The Press Run

As the plate cylinder spins in the offset printing machine, it contacts rollers that distribute a water solution onto the plate. The ink then adheres to the image areas while the water solution repels ink from the non-image sections. The subsequent roller in the sequence is surrounded by a rubber blanket, which is called the offset or blanket cylinder. It turns in the opposite direction of the plate cylinder, and as the two cylinders roll against one another, the water on the plate is squeezed away and the ink is transferred.

The third and final roller in the sequence is called the impression cylinder. It turns in the opposite direction of the second cylinder and presses the paper against the rubber blanket to transfer the ink to the paper. At this point, the image on the paper is identical to the image on the plate.

Step Three: Bindery

During the bindery step, the printed product is completed. The huge rolls of newly-printed paper and cut and put together so that the pages fall in the intended order. Also, pages are bound together by staples or glue. In some cases, a machine known as a stitcher takes the folded printed paper and collates them together. Finally, stitches are inserted into the pages, tying them together.

Concord, NC Offset Printing

Now that you have an idea of how offset printing works, you can contact the experts at iTek to complete your large print job. Our Concord, NC printing company takes every project seriously and stays ahead of the trends and evolution of the printing industry. To get the ball rolling on your offset printing project, give us a call at (704) 457-7687.