Offset Printing

Offset printing is a widely used printing technique where ink is transferred from a plate to a rubber blanket and then onto the printing surface. Here's how it works:

Plate Preparation: The image to be printed is transferred onto a metal plate. This is typically done through a process called "burning" or "exposing," where the plate is exposed to light through a film negative or digitally generated image. The areas of the plate exposed to light become chemically treated, while the unexposed areas repel ink.

Ink and Water: The plate is mounted onto a cylinder on the printing press. Ink is applied to the plate, adhering to the image areas due to their chemical properties. At the same time, a dampening system wets the non-image areas of the plate to repel ink.

Transfer to Blanket: As the plate cylinder rotates, it comes into contact with a rubber blanket cylinder. The inked image is transferred from the plate to the rubber blanket. This transfer process helps protect the plate and ensures a consistent ink application.

Transfer to Substrate: The rubber blanket cylinder then makes contact with the substrate (usually paper), transferring the inked image onto the surface of the paper. The paper passes between the blanket cylinder and another cylinder called the impression cylinder, which applies pressure to ensure proper ink transfer.

Drying: After the ink is transferred to the paper, it needs to dry before handling or further processing. Depending on the type of ink used and the printing conditions, drying may occur through evaporation, absorption, or the application of heat.

Offset printing is known for its high image quality, consistency, and versatility. It is suitable for large-volume print runs and supports a wide range of paper types and finishes. Offset printing is commonly used for producing items such as books, newspapers, magazines, brochures, posters, and packaging materials. While the initial setup costs for offset printing can be higher compared to digital printing, the per-unit cost tends to decrease with larger print runs, making it cost-effective for large-scale projects.