Offset printing: Everything you need to know

freepik.com
If you’ve approached the world of printing, you most likely have heard about the different types of printing. One of the most popular methods is printing offset and for all the good reasons. As such, the printing industry relies on this type of technique because it applies to many products and provides amazing quality.
Unlike other printing methods, offset printing is known for producing clear, sharp, and accurate images, even in large volumes. Not only that, it also enhances the value of products and packaging, making it an ideal choice for other industries too.
So, if you work in publishing and need some ideas for your next packaging project, offset printing might be the solution for you. Here you’ll learn about the basic details and then decide if it’s the right choice for your project.
What is offset printing
Although it’s an old form of lithography, offset printing has evolved in time, especially from a technological point of view. Nowadays, the publishing market is constantly increasing, and offset printing is no exception. According to statistics, the Offset Printing Machines market is estimated to grow at a size of $3262.1 million in the next five years.
During the process, the ink rollers are transferred from a plate to a blanket (or rubber roller). After being plated, the image goes onto a flexible rubber sheet, where it has to pass through the press. Then, the image transferred in a paper and that’s how it gets its name ‘’offset’’ – due to the ink being offset to the rubber blanket and the paper.
Additionally, offset printing is most widely used in mass production for producing large quantities, such as:
- Newspapers
- Magazines
- Brochures
- Banners
- Posters
- Boxes
- Postcards
- Product leaflets
That’s why the demand for offset printing is constantly increasing, especially since its ability to produce high-quality images and designs is unmatched.
The process of offset printing

freepik.com
The mechanism of offset printing may seem complex but it’s very straightforward. The base of offset printing depends on the separation of oil and water. In addition, the plates’ job is to make image areas drawn to ink and non-image areas drawn to water to push back against the ink. So, when the ink and water are applied, the water is attached to the non-image area, while the oil-based ink is attached to the image.
Essentially, this method is based on a type of mechanism that’s made of three cylinders:
- Matric (plate cylinder)
- Blanket cylinder
- Pressure cylinder
The first step starts with the first cylinder, also known as the matrix. This is a rather thin cylinder, made of aluminum or plastic plates. This cylinder is already made to have the images stick to ink and avoid water, so when the plate spins, the rollers apply both the ink and water.
Second, the next cylinder is the ‘’offset blanket’’ one and it has a rubber blanket attached to it, which turns in the opposite direction. Both cylinders start rolling at the same time, squeezing the water and transferring the ink onto the rubber blanket.
Lastly, the third cylinder in the offset printing is the pressure cylinder and is made of clean steel. This cylinder also rolls in the opposite direction against the blanket one, as it transfers the ink by pushing it against the rubber blanket.
One of the best advantages of offset printing is its ability to print fast. For example, they can print up to 120,000 pages hourly, which is around 18,000 sheets per hour. Additionally, each sheet has approximately 48 A4 pages.
Offset printing stages
Offset lithography goes through various printing steps, but the most common ones include the pre-press stage, the printing stage, and the post-press stage. Let’s go briefly over them:
The pre-press stage
The first step in the offset printing process involves preparing the files for printing. This includes many activities, such as layout, designing, and typesetting. The main goal for this initial stage is to ensure the final product meets the specifications. Also, this is the time to make any adjustments, check whether the files are the appropriate size, and if they’re in the correct color.
The printing stage
The next stage is the printing stage which is used to transfer ink from the printing plates to blanket cylinders and lastly on paper. One of the best advantages of this stage is how the ink is transferred onto the paper through the blanket cylinder, forming a consistent application.
The post-press stage
The last step of the offset printing process is the post-press stage. During this step, the materials are finished up and prepared for distribution. This means cutting and trimming the edges of the materials for a neater look and adding any special coatings for a more polished look.
Advantages of offset printing
Being one of the most commonly used methods in the publishing industry, offset printing has various advantages. This method is useful for many reasons, such as:
- It’s a cost-effective method for larger quantities
- Can accommodate different paper types, along with personalized finishes
- The more you print, the less you’ll pay per page
- Different custom inks (fluorescent or metallic)
- Provides high-quality and accurate prints