What Are Uses of Offset Printing Plates

In offset printing, the printing plate is the core component, and its performance directly affects the printing quality and efficiency. At present, there are mainly the following types of common offset plates, which have their own application advantages in different fields.

Common types of offset plates

PS plate (pre-coated photosensitive plate)

PS plate is one of the most widely used offset plates at present. It uses a thin aluminum plate as the substrate, and the surface is coated with a photosensitive layer. After exposure, development and other processes, the printed image is formed. PS plate has the characteristics of high resolution, strong printability (usually up to 100,000 prints or more), moderate cost, and easy operation, which can meet the quality requirements of most printed products.

CTP plate (computer-to-plate)

CTP plate is a new type of offset printing plate that has emerged with the development of digital technology. It does not need to go through the traditional film platemaking process. The computer can directly transmit the image and text information to the platemaking machine for exposure and development, which greatly shortens the platemaking time, reduces the quality loss in the image transmission process, and improves the printing accuracy and consistency. The ctp plates for offset printing also have excellent printability and can better meet the needs of high-speed printing and multi-color printing.

Aluminum-based photosensitive resin plate

This plate uses aluminum plate as the base material and is coated with a photosensitive resin layer on the surface. It has good elasticity and solvent resistance, good image and text reproduction, and is suitable for printing fine lines and dots. However, its printability is slightly lower than that of PS plate and CTP plate, generally around tens of thousands of prints, and is often used for some printed products with high requirements for printing quality but small print volume.

Multi-layer metal plate

Multi-layer metal plate is a composite of different metal materials, such as copper-nickel-chromium multi-layer metal plate. It has high surface hardness and extremely strong printability, which can reach more than one million prints, making it very suitable for large-scale and long-term printing operations. However, due to its complex production process and high cost, its application range is relatively narrow.

Application of offset printing plates in different fields

News and publishing fields

In the field of news publishing, the printing of newspapers and periodicals is more sensitive to timeliness and cost. PS plates have become one of the common newspaper press plates due to their moderate cost, fast platemaking speed, and printing durability that can meet the newspaper printing volume (usually tens of thousands to hundreds of thousands of copies per issue).

For some journals with high printing quality requirements and relatively stable printing volume, CTP plates are increasingly widely used. The high precision and fast plate-making characteristics of CTP plates can make the pictures and texts in the journals clearer and more beautiful, and improve the overall quality of the journals.

Commercial printing field

Commercial printing covers brochures, posters, albums, samples, etc., which have high requirements for printing quality, and require fine image and text reproduction and stable color performance. CTP plates play an important role here. Its high-precision platemaking ability can accurately present complex patterns and delicate color levels, meeting the pursuit of high quality in commercial printing. Many companies use CTP plates for printing product brochures, high-end posters, etc.

For some commercial printed products with small print volumes and strict cost control, such as leaflets for small companies, aluminum-based photosensitive resin plates are also a good choice. It can reduce costs while ensuring a certain printing quality.

Packaging and printing field

Packaging and printing usually have large print volumes and require high print durability of the plate. Multi-layer metal plates are often used for large-scale packaging and printing due to their super print durability, such as food packaging boxes, beverage bottle labels, etc. They can maintain the stability of images and texts during long-term printing processes, ensuring consistent printing quality for each package.

At the same time, CTP plates are also widely used in packaging and printing. As packaging designs become more and more exquisite, the requirements for printing accuracy and color reproduction are also getting higher and higher. CTP plates can meet these requirements, making the patterns and texts on the packaging more vivid and clear, and improving the packaging grade of the product.

Book printing field

Book printing varies depending on the type of book. For best-selling books, textbooks, etc. with large print volumes, both PS plates and CTP plates are used. PS plates can meet the printing needs of general books and have relatively low costs; CTP plates are more suitable for printing picture albums and hardcover books with rich pictures and high quality requirements, which can make the pictures in the book more colorful and the text clearer.

Aluminum-based photosensitive resin plates are generally used for niche books or special printed materials with small print runs due to their relatively low print durability.

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