What Is Offset Printing and How Does It Work?

Offset printing makes commercial printing cost-effective. If you are in the printing industry that deals with a large number of orders for packaging, labels, barcodes, books, brochures, newspapers, stationery items, and more. It is fast, efficient, and produces high-quality prints with the least per unit cost.

What is offset printing? Offset printing, lithographic printing, offset lithography and planographic printing are all the same thing. All these terms refer to the same offset printing process. Offset means transfer. The oil-based ink is transferred from an aluminum plate onto a rubber blanket through impression due to rotating cylinders, and finally onto the substrate. It involves three cylinders i.e. plate cylinder for aluminum plate, blanket cylinder for rubber blanket, and impression cylinder for a substrate that rotates opposite to one another. It transfers the print from one surface to another through impressions. Therefore, it is known as the 3-cylinder offset printing press.

How does Offset Printing Work?

In an offset printer, there are four different printing units each printing colors in the sequence Cyan, Magenta, Yellow, and Black. As we will be discussing in the stage 1 process, the digital image is separated into CMYK format so that each of the colors is printed in the dedicated units. So, let us look into the details of the offset printing process.

Stage 1:

The digital print files are a combination of four different colors, i.e. Cyan, Magenta, Yellow, and Black. At the pre-press stage of the offset printing, the digital files are separated into these four-color versions.

Stage 2:

Each of these colors is laser printed onto the aluminum plates that results in an image and non-image area.

Stage 3:

Then it loaded onto a roller known as a plate cylinder. The cylinder with the aluminum plate revolves in a circular manner that moistens the non-image/blank area of the aluminum plate with water from the dampening system. Then the oil ink passes through a series of rollers onto the image area of the plate. This image on the aluminum plate is “offset” or transferred onto another cylinder with a rubber blanket known as a blanket cylinder.

Stage 4:

Finally, the paper passes between the blanket cylinder and the impression cylinder where it receives the printed image. That is to say, in the first printing unit of the offset printing press, the paper or compatible substrate is printed with cyan. In the second unit, it is printed with magenta, yellow in the third, and finally the blank print. Therefore, we get a clear and sharper final image on the substrate as the digital print file.

Offset Printing vs Digital Printing: Which is Better?

Offset and digital printing have various uses in different application areas. It is mostly your business that requires the right print method. Let us look into the details of each printing method.

1. Offset printing needs pre-printing preparation:

Offset printing needs preparation prior to starting the printing process. It needs a flat aluminum plate that is used to transfer ink onto a rubber blanket and then onto the substrate.

Whereas digital printing is done by the electro-photographic printer. You can directly feed paper into the printing machine.

2. Both Offset and Digital Printings Works with CMYK Configuration:

Both Offset and Digital Printings Works with CMYK Configuration. Indeed, many brands have defined their own set of colors. Therefore, with offset printing, you can also use the Pantone color palette which enables to use of some special and additional colors.

3. Digital Printing is Fast & Easy-to-Perform Compared to Offset Printing:

Digital printing gives you a lot of freedom when it comes to printing on a variety of substrates. Moreover, digital printing is fast and quickly delivers the final product. As opposed to offset printing, you need to spend additional time setting up or preparing a matrix specifically for every single project. Additionally, digital printing is easy to perform.

4. Offset Printing is Cost-effective:

Offset printing guarantees high-quality final print in addition to being cost-effective for high volume print production. For bigger projects, offset printing offers the lowest per unit printing prices compared to digital printing.

To summarize:

If you need to print large numbers of signs, banners, and packaging items, i.e. for industrial or commercial print production, offset printing is the perfect solution for you. It reduces per unit cost with increased profits. On the other hand, if your current business needs aren’t so high as for printing 500 or fewer orders, go with digital printing.

Offset vs Silk screen printing:

Silk screen allows single color printing:

Silkscreen printing allows you to make color-specific films to individually apply in different areas as per the design. If you are printing colors of a pattern or the number of colors is small, then silk screen printing is the most suitable choice.

Offset Printing is suitable for CMYK or multiple-color printing:

Offset printing is also known as CMYK printing that applies four layers of ink. If you want to print solid and vivid colors, then silkscreen is the right choice.

To summarize:

Both offset and silkscreen printing have slightly different use cases. Offset printing is best for photos and gradient colors i.e. CMYK color configuration. Whereas silkscreen printing is suitable for both Pantone & CMYK color formats.

You can print apparel, steel, aluminum, wood, and brass materials in silkscreen printing whereas offset printing is suitable for packaging items, labels, and stickers.