Litograafiaplaadid

Litograafiaplaadid are specialized surfaces used in the printing process of lithography. Traditionally, these plates were made from a smooth, fine-grained limestone. The principle behind lithography relies on the chemical repulsion between oil and water. The image is drawn onto the limestone using a greasy crayon or ink. After the drawing is complete, the stone is treated with a solution of gum arabic and nitric acid. This process etches the image into the stone and creates a non-image area that is receptive to water. When water is applied to the plate, it adheres to the non-image areas. When ink is then rolled onto the plate, it adheres only to the greasy image areas and is repelled by the water in the non-image areas. Paper is then pressed against the inked plate to transfer the image. Modern lithography often employs thin metal plates, typically aluminum or polyester, which are treated with light-sensitive coatings. These plates offer advantages in terms of weight, durability, and the ability to print from a press rather than directly from a stone. The preparation and maintenance of lithographic plates are crucial for achieving high-quality prints.