Offset printing is one of the most widely used printing methods in the industry, favored by many businesses due to its high quality and ability to print large quantities. This method works by indirectly transferring ink to the printing surface, ensuring images and text are printed with high precision and clarity.
One reason for offset printing’s popularity is its cost-effectiveness at high volumes and its ability to use a wide range of color combinations. These features make it ideal for printing books, newspapers, promotional packaging, and many other printed products. In this article, we’ll answer the question: What is offset printing and what are its characteristics? Stay with us until the end.
Contents
What is offset printing?
In response to the question “What does offset printing mean?”, offset printing is a common method in theprinting industryindustry, used to produce printed materials in high volumes with excellent quality. This method is based onLithographytechnology, where ink is first transferred to metal plates and then indirectly to the printing surface via a silicone rubber blanket. This process ensures the final print has high precision and clarity, with colors applied uniformly and vividly.
One important type is web offset, where paper is fed continuously from rolls and printed at high speed. This model is used for newspapers, magazines, and other high-volume printed materials. Due to its ability to use mixed colors and high quality, offset printing is an ideal choice for printing brochures, books, promotional packaging, and magazines.
What are the types of offset printing methods?
Offset printing is performed using various methods, some of which are no longer commonly used due to high costs, time consumption, and poor quality. Today, two main methods remain prevalent in the offset printing industry, which we’ll explore below.
Traditional Offset Printing
In this method, the contrast between water and oil forms the basis of the process. Areas of the printing plate meant to receive ink are oil-receptive, while non-printing areas are water-receptive. This difference ensures ink is applied only to desired areas, transferring the image to the printing surface with high precision.
Modern Offset Printing
Modern offset printing is fully digital and controlled by computer software. In this method, the design file is first checked for CMYK color composition, then plates and zinc sheets are prepared accordingly. This technology increases printing speed and improves final quality. It also offers higher color accuracy compared to other printing methods and is highly cost-effective for mass production.
To learn more aboutthe difference between flexo and offset printingand their applications, click here.
Useful tips about the offset printing process
- For offset printing, you must use the CMYK color system.
- Offset printing is based on four-color printing. However, you can print jobs with 1 to 10 different colors (with one color varying from light to dark). Printing more than four colors requires specialized knowledge and expertise.
- Offset printing machines are either single-color, two-color, or four-color. Of course, machines capable of printing more than four colors also exist.
- In offset printing machines, each color has a separate printing unit consisting of a plate cylinder and ink rollers. (Note: In some machines, such as Roland made in the USA, two colors are mounted on one tower.)
- In single-color machines, each color is printed separately. For example, a four-color job must pass through the machine four times, with colors adjusted each time. Therefore, it’s better not to use this type of machine for four-color jobs, as experience has shown the final result will be unacceptable.
Also, it’s good to know thatUV printingis one of the advanced technologies in offset printing services, creating shiny, attractive effects that multiply the quality and beauty of the final print.
Some minor factors affecting offset print quality
What are some minor factors affecting offset print quality? Printing engineers often debate the impact of various factors — especially in offset printing — where all necessary components are present. The result always reflects the interaction of content, materials, and execution. Below are some of these factors:
- Ink quantity determines the required amount of dampening solution.
- Rollers must be properly calibrated relative to each other for correct ink transfer.
- Rollers must have sufficient resistance to transfer ink.
- The printing plate and blanket play a crucial role in transferring ink to the substrate.
- Ink type, viscosity, and flow significantly affect print quality.
Other influencing factors inUV print quality:
- Type of zinc plates used
- Type of paper used
- Type of ink used
- Type and cleanliness of rollers
- Resistance, printability, and pressure (impression) applied to the paper
Applications of offset printing
- Printing books, magazines, and newspapers
- Producing packaging and labels
- Printing brochures, catalogs, flyers, and posters
- Producing office stationery and customer documents
- Environmental advertising and promotional gifts
What are the advantages of offset printing?
In the printing world, choosing the right method greatly impacts final quality and cost. Offset printing’s advantages make it an ideal choice for mass production. Below, we’ll review the benefits of offset printing.
The table below explains the advantages of offset printing:
Row | Feature | Description |
1 | High print quality | Produces images with high resolution and detail; ideal for magazines, brochures, and promotional packaging |
2 | Cost-effective for high-volume printing | Unit cost decreases with increased quantity; economical for large projects |
3 | Variety of printable materials | Can print on paper, cardboard, fabric, leather, metal, and suitable for label rolls and packaging |
4 | High printing speed | Fast machine operation; suitable for time-sensitive projects |
5 | Consistent, uniform print quality | Maintains consistent quality from first to last copy using advanced ink control |
Considering these advantages, offset printing remains one of the most widely used techniques in the printing industry and is an ideal choice for projects requiring high quality, mass production, and economic cost.
What are the disadvantages of offset printing?
Offset printing, as one of the common methods in the printing industry, has several disadvantages in addition to its many advantages, which we’ll address below.
Row | Drawback | Description |
1 | High setup cost and time | High initial cost for plates and setup; not economical for low quantities |
2 | Lack of flexibility for changes after printing begins | Changes are impossible after printing starts; design must be finalized beforehand |
3 | Time-consuming printing process | Long preparation due to plate and zinc production; delivery may take up to 15 days |
4 | Limitation for low-volume printing | High cost for low-quantity prints; digital printing is a more suitable option |
5 | Sensitivity of printing plates | Aluminum plates are vulnerable to oxidation; require special storage |
Considering these drawbacks, choosing the right printing method depends on project needs, budget, and timeline.
By carefully following theoffset printing process steps, high-quality printed results can be achieved, which are very important for promotional and commercial products.
Printing machine dimensions:
Offset printing machines come in various sizes from 25×35 cm to 100×140 cm. Choosing the right machine size, especially for high volumes, plays an important role in cost reduction. For example, printing a 25×35 cm job with 10,000 units can be done in two passes with a 50×70 cm machine or one pass with a 70×100 cm machine — the latter being more cost-effective. However, film and zinc costs should also be considered, as they may not differ significantly for low or medium quantities.
Common classification of offset printing machines:
- 25×35 cm machine: The oldest and smallest offset machine, usually single-color.
- GTO (35×50 cm) machine: Common in printing houses, available in single-color and four-color models. Newer models (e.g., 2004 and above) offer higher precision and quality.
- Two-sheet (50×70 cm) machine: The most widely used offset printing machine, suitable for many orders.
- Four-and-a-half-sheet (70×100 cm) machine: Suitable for large jobs or high volumes.
In four-color printing, lithography prepares four zinc films, which operators align on the machine using registers.
Advanced Machines and Professional Printing Services at Nami Naghsh:
AtNaminaghsh Printing, we take pride in offering a wide range of offset printing services with the highest quality, using modern, up-to-date global equipment. One of our advanced machines is a 6-color web offset press, capable of producing prints with exceptional quality and precision. Additionally, with our flexo tower and rotary UV unit, we produce the finest label versions, giving your product a unique glossy or matte finish.
To inquire about single-color offset printing prices, pleasecontactus.