What is offset printing plate? Popular types of plates today

What is an Offset Printing Plate?

An offset printing plate is a zinc plate coated with a light-sensitive diazo layer, usually blue in color. It is also known as a printing plate used for mounting on an offset printing machine to carry out printing. The plate plays a crucial role in transferring images from the computer design to the printed product. The quality of the plate significantly affects the quality and cost of the printed output.

Learn more: What is an Offset Printing Machine?

Common Types of Offset Printing Plates

Non-Processed Offset Printing Plate

A non-processed offset printing plate (also known as unprocessed or no-wash plate) is a special type of plate in the printing industry, particularly in offset printing. Non-processed plates do not require chemical processing after imaging, helping to reduce environmental impact and save time.

Advantages of Non-Processed Offset Printing Plates

• • No Chemical Processing Required: After imaging, the plate does not need washing or chemical processing like traditional plates, saving time and processing costs.
  • Environmentally Friendly: Eliminates or minimizes the use of chemicals, reducing harmful waste and making it safer for users and machine operators.
  • High Durability and Quality: Non-processed plates are typically made from high-quality materials, ensuring durability and image accuracy, suitable for high-quality printing jobs.
  • Wide Applications: Widely used in offset printing jobs, from small to large scale.

Disadvantages of Non-Processed Offset Printing Plates

• • High Initial Investment Cost: Equipment and materials for non-processed plates are often more expensive than traditional plates.
  • High Technical Requirements: Requires advanced technology and machinery for imaging and plate processing.

Non-processed offset printing plates are becoming increasingly popular and preferred in the modern printing industry due to the benefits they offer.

Processed Offset Printing Plate

A processed offset printing plate (also known as a chemical-processed plate) is a traditional type of plate used in offset printing, requiring chemical processing after imaging to complete the plate. This process includes steps such as washing, developing, and fixing the image on the plate.

Advantages of Processed Offset Printing Plates

• • High Durability and Quality: Processed plates are typically made from high-quality materials, ensuring durability and image accuracy, suitable for high-quality and large-volume printing jobs.
  • Lower Initial Investment Cost: Processed plates are an economical and effective choice due to their lower initial investment cost and easy availability of materials and equipment.
  • Wide Applications: Widely used in offset printing jobs, from small to large scale.
  • Availability: The necessary materials and chemicals for this process are readily available in the market.

Disadvantages of Processed Offset Printing Plates

• • Time and Labor Intensive: The chemical processing process is complex and time-consuming.
  • Chemical Costs: High costs for purchasing and processing chemicals.
  • Worker Safety: Harmful to the health of machine operators.
  • Environmental Impact: The use and disposal of chemicals can harm the environment if not managed properly.

Processed offset printing plates are a popular choice in the offset printing industry, especially for large-volume and high-quality printing jobs. However, with the development of technology and environmental awareness, non-processed plates and digital printing technologies are becoming increasingly preferred.

Learn more: What is Huaguang 2-Layer TP-EE CTP Plate?

Applications of Offset Printing Plates

Offset printing plates are primarily used in offset printing. Their specific applications are as follows:

Design and Film Output

When applied to offset printing, the first step is designing and outputting the film. The plate is used to transfer the image from the original design to the offset printing plate, acting as a template. During this process, the image is separated into color layers, and the sharpness of the image is determined to ensure printing quality.

Imaging (Plate Exposure)

The plate is placed into a plate-making machine—a crucial device in the printing industry that converts digital data into physical printing plates. The image or content to be printed is projected onto the plate surface using UV or laser beams, creating printing and non-printing areas on the plate. This process transfers the image from the film to the plate, producing an accurate offset printing template with the desired details and colors.

Chemical Processing (For Processed Plates)

After the imaging process, the plate is placed into a plate-developing machine. This is a crucial step in transferring the image from the exposed plate to a ready-to-print state. The process involves using special chemicals to remove the photosensitive layer in areas exposed to the laser. Steps include developing, washing the plate, and protecting the surface.

Mounting the Plate on the Offset Printing Machine

After the above steps, the plate is mounted onto the plate cylinder of the offset printing machine. The plate has printing elements (ink-receptive) and non-printing elements (water-receptive). The printing elements transfer ink from the ink rollers to the blanket cylinder, and then the ink is transferred to the paper. The offset printing process can accurately reproduce images and colors, improving printing quality. It also allows for high-volume and high-speed printing, suitable for industrial and commercial printing.

Factors Affecting the Cost of Offset Printing Plates

Production Costs

• • Materials: The cost of materials used to produce the plates, including metal and chemicals, directly affects the cost. Higher-quality materials will cost more.
  • Labor: The labor cost for producing and processing the plates. Areas with higher labor costs will increase the product price.
  • Machinery and Equipment: Investment in modern technology and equipment may increase initial production costs but can reduce long-term costs and improve efficiency.
  • Production Process: Automated and optimized production processes can reduce labor costs and production time.

Accuracy and Detail of the Print

• • Resolution: Plates with higher resolution can reproduce small and complex details more accurately but require more effort and cost to produce.
  • Image Quality: Higher image quality requirements demand advanced technology and skilled technicians, increasing production costs.
  • Complex Designs: Designs requiring many details and colors take more time and effort to produce, increasing costs.

Durability and Lifespan of the Plate

• • Material: Using high-quality materials increases the plate’s durability, allowing for multiple prints without damage, but at a higher initial cost.
  • Production Technology: Technologies like CTP (Computer-to-Plate) increase the plate’s durability and lifespan by reducing physical contact during production.
  • Protective Coatings: Plates can be coated with special protective layers to resist wear and increase lifespan, but this increases production costs.

Quantity of Printed Products

• • Mass Production: Large-volume printing typically has lower costs per unit due to economies of scale. The cost of plate preparation and machine setup is spread over many products.
  • Small-Volume Printing: For small-volume printing, the preparation and setup costs remain the same, leading to higher costs per unit. This does not optimize the production process and materials.
  • Quantity Discounts: Suppliers may offer discounts for large-volume printing, reducing the cost per print.

Supplier

• • Supplier: The cost of plates may vary between suppliers. Reputable and experienced suppliers often provide higher-quality products but at a higher price. Conversely, new or less reputable suppliers may offer lower prices but with uncertain product quality.

Where to Buy Reliable Offset Printing Plates?

Offset printing plates are an indispensable part of modern offset printing technology. They establish a crucial link between the original design and the final printed product. The quality of the plate significantly affects the quality and sharpness of the printed product. High-quality offset printing plates produce prints with excellent detail and color, enhancing the value of the printed product and boosting the effectiveness of printing campaigns.

We understand that finding high-quality and reliable offset printing plates can be challenging due to the many suppliers in the market. Therefore, An Quang Joint Stock Company, with nearly 20 years of experience in the packaging printing industry, is committed to providing customers with the best quality products and services at reasonable prices.

We hope that all the above information will help you better understand offset printing plates. If you have any questions or need to purchase offset printing plates, please contact us via the hotline 0968866338 or message us on our fanpage: www.facebook.com/anquangjsc.

An Quang Joint Stock Company is honored to serve you!