en English
ar Arabicen Englishfr French

What Is Offset Printing

Home Blogs What Is Offset Printing

Offset printing, also known as offset lithography, is a printing press method that transfers the ink from a plate to a rubber roller, then to various substrates to provide high-quality images and designs.

This printing process is called “offset” because it does not transfer ink directly onto paper as other printing methods do. So rather than going from plate to paper in two steps, ink is transmitted first to a rubber cylinder and then printed on paper. Also, it only uses three cylinders, namely plate cylinder, offset blanket cylinder, and impression cylinder. Offset printing is generally used for mass production, such as printing large quantities of brochures, newspapers, magazines, and of course, offset printing boxes.

What Does Offset Lithography Printing Mean?

The term “lithography” started in the late eighteenth century when the Bavarian limestone was used as a printing surface. Its invention made printing a more comprehensive range of marks and tone areas possible than the earlier printmaking techniques. Moreover, lithography made printing with color easier.

At present, offset lithography includes printing an image or text onto an intermediate surface before the final sheet. The method is ‘offset’ since the plate does not directly contact the paper, preserving the plate’s quality. The image is reversed twice with offset lithography and appears on the final sheet the same way round as on the stone or plate.

Offset Printing Processes

The Pre-Press Process

Preparing the project and offset printing supplies before jumping through the offset printing machine and starting the process is essential to producing the exact output. Unfortunately, one of the common mistakes people make during their project preparation is not converting their design from RBG (red, green, blue) to CMYK (cyan, magenta, yellow, black).

The best way to ensure you are correctly getting your files is by contacting a product specialist of the printing company you have business with.

 

How does offset printing work?

Offset printing machine feeder
Source: Pinterest

The first cylinder utilized in the offset printing machine is the plate cylinder. This thin cylinder has an aluminum or plastic plate surrounding it. Each plate is customized according to the images and texts to be printed onto the paper. The plate cylinder has been pretreated to have the images or texts attract ink and repel water. When the offset printing plate cylinder rotates, it will make contact with rollers that will use the ink and water.

The second cylinder is the offset blanket cylinder. This next cylinder has a rubber blanket around it and spins opposite to the plate cylinder. When both cylinders roll or turn against each other, the water is squeezed away, and then the offset printing ink is transmitted onto the rubber blanket. This creates a reflection image of the ink design.

The third cylinder is the impression cylinder, which is made of clean steel. The cylinder, this time, turns against the direction of the blanket cylinder. The impression cylinder passes on the offset ink as it presses paper against the rubber blanket.

What’s really impressive with offset printing machines is that they are fast and efficient. In fact, they can print up to 18,000 sheets every hour, with each sheet containing up to 48 pages of letter-sized content or A4-sized paper. Thus, a common offset printing press can print eight pages in one sheet, precisely translating to 120,000 pages each hour.

 

How to run an offset printing machine?

Before starting a new print run, the offset printing plates should be replaced, and several pages are printed to verify if the quality is in optimal condition. This is called the “make ready” time, which lasts up to 15 minutes depending on the complexity of the printing task. If you are printing on a single color printing machine, you need to first clean the offset ink system before printing another color.

To begin the “make ready” process, the imaged offset plates are clamped onto the plate cylinders, and the settings are adjusted for offset ink density. An initial batch of sheets is printed at a low speed, and the color registration and the ink/water balance are inspected.

Types of Offset Printing

printing-machine
Source: Pinterest

The offset printing process is one of the most widely used printing methods due to its high-quality output and consistent results. There are two kinds of offset printing, namely web and sheet-fed offset printing.

 

What is web offset printing?

Usually, web offset printing is seen in newspapers, magazines, and brochures or pamphlets used in trade shows because this method performs a continuous paper feeding by the press machine. No wonder it can provide over 5,000 printed materials. Then, the rolls of paper are cut afterward to create similar sheets.

Interestingly, a web offset printing machine can generate more than 3,000 papers per minute, translating to 80,000 identical sheets every hour. Hence, this selection is perfect for companies that need to print large quantities quickly to meet deadlines.

 

What is sheet-fed offset printing?

Different from the web offset printing process, sheet-fed offset printing produces smaller quantities since sheets of paper are fed individually. Still, it is deemed a quick printing choice compared to other printing methods available.

What’s amazing is that sheet-fed lithography can print 12,000 sheets up to 24,000 per hour. Moreover, throughout the years of modernization, sheet-fed printing has also improved in speed, allowing it to perform similar functions as the web offset lithography.

Offset Printing Advantages and Disadvantages

 

Advantages of Offset Printing

If you want to know the number one list in terms of offset printing advantages, then quantity hits the top spot. This is because offset printing produces larger quantities in a more cost-effective way than other printing types.

Suppose you prefer metallic ink for your perfume box printing or a unique paper type for your project, then offset printing is ideal. This is because offset printing packaging is flexible and offers tons of material, ink, and finishes options.

Indeed, size matters for finished projects. Fortunately, offset handles a wide variety of large sizes that other printing presses cannot often accommodate.

When applying the PMS (Pantone Matching System) for printing in color, offset printing gives a more precise color matching since it uses Pantone ink. This is essential when reproducing logos or other color-specific images.

 

Disadvantages of Offset Printing

Since the offset printing process involves creating plates and performing the transfer, this operation needs more setup time. So if you need to do a last-minute project, quick turnaround, or any time-sensitive circumstance, offset printing is not the best choice.

If you want tailor-made pieces like postcards, letters, or direct mail items that need various information, such as addresses, offset printing is not the top pick for this feature.

Since offset printing requires extra time for setting up, it would not be wise to use this method on smaller batches. It is not cost-efficient.

What is offset printing used for?

The offset printing process could be your best choice when it comes to larger print jobs. In addition, it is said to be much more explicit than other printing methods. In fact, even if other printing processes are catching up to technological innovations, offset lithography is still in demand because it offers clearer and better results. Furthermore, since offset lithography ensures higher color consistency, versatility, and allows printing on various materials, like plastic, paper, wood, or even metal, it is preferred by many industries.

So what is offset printing used for? It is usually used by individuals who need highly detailed texts and images with rich colors. In addition, offset lithography is often used to print high-quality promotional materials, like branded coasters, mugs, mouse mats, and so on. It can also be used to print perfume boxes, hotel brand over door hangers, tent cards, plastic menus, and other things.

Conclusion

If you think your project will require large quantities to be printed but have a tight budget, offset printing could be your best solution. Also, choosing this method can guarantee a better outcome since it offers richer colors. So, if you have decided to choose this method and need an offset printing and packaging company, go to Hongyi. We can definitely assist you with your all printing box needs.

Wonderful! Share this Case:

Get A Quote

    Custom Perfume Boxes Make Your Brand Shine.

    Let your perfume brand be known the world over with unique packaging brought by your custom perfume box manufacturer Hongyi.

      Upload Your Document

      ADD A FILE

      Please upload a file in AI, JPG, PNG, PDF, DOC, or TXT.

      *We respect your confidentiality and all informations are protected.

        Upload Your Document

        ADD A FILE

        Please only upload a file in PDF or JEPG.

        *We respect your confidentiality and all informations are protected.

        Let's Customize Your Design.