Project Description

Offset / Lithography
Offset lithography, often referred to simply as offset printing, is a commonly used printing technique for producing high-quality printed materials in large quantities. It is based on the principle of repulsion between oil and water.

Here’s how the offset lithography process generally works:

Image Preparation: The image to be printed is transferred onto a metal plate, usually aluminum, using a photosensitive chemical process. This plate contains areas that attract ink (the image areas) and areas that repel ink (the non-image areas).

Ink and Water Application: The plate is dampened with water, which adheres to the non-image areas but is repelled by the image areas. Ink is then applied to the plate, adhering to the image areas due to their affinity for oil-based substances.

Transfer to Blanket: The inked image on the plate is transferred (offset) onto a rubber blanket cylinder. This transfer occurs because the rubber blanket is more flexible than the metal plate, allowing it to conform to the contours of the printing surface.

Printing: The image is then transferred from the rubber blanket cylinder onto the printing substrate, typically paper or cardboard, as it passes between the blanket cylinder and the impression cylinder. The substrate absorbs the ink, creating a printed image.

Drying: After printing, the ink on the substrate needs to be dried to prevent smudging and ensure proper adhesion. This can be achieved through air drying or the use of drying units equipped with heaters.

Offset lithography is known for its ability to produce sharp, high-resolution images with vibrant colors and smooth gradients. It is widely used for printing a variety of materials, including books, magazines, newspapers, brochures, posters, packaging, and more. Offset printing is particularly well-suited for large print runs due to its efficiency and cost-effectiveness.