Prepress Preparation: The process begins with prepress preparation, where digital files or physical artwork are prepared for printing. This may involve converting digital files into a format suitable for printing, color separation (if necessary), and creating printing plates. Plate Making: Offset printing uses metal plates, typically made of aluminum, coated with photosensitive chemicals. These plates are exposed to UV light through a film negative or computer-to-plate (CTP) process, which creates the image to be printed on the plate. The areas exposed to light become chemically treated, while the unexposed areas are washed away, leaving the image on the plate. Plate Mounting: The printing plates are mounted onto plate cylinders on the printing press. Each plate corresponds to one color in the final image (e.g., cyan, magenta, yellow, and black in CMYK color printing). Inking the Plates: The plate cylinders pass through a series of ink rollers, which apply ink to the image areas on the plates. The ink is oil-based or water-based, depending on the type of printing press and the substrate being printed. Transferring to Blanket: As the plate cylinders rotate, the inked image is transferred from the plates to a rubber blanket cylinder. The rubber blanket is slightly offset from the plate cylinder, which is where the term "offset printing" comes from. This offsetting helps ensure a smooth and consistent transfer of ink to the printing surface. Printing: The printing surface, typically paper, is fed through the press and comes into contact with the rubber blanket cylinder. The inked image is then transferred from the blanket onto the paper. Each color is applied sequentially, with the paper passing through the press multiple times if necessary to build up the full-color image. Drying: After printing, the ink on the paper needs to dry before handling or further processing. This may be accomplished through air drying, infrared drying, or heatset drying, depending on the type of ink and substrate used. Finishing: Once the printing is complete, the printed sheets may undergo various finishing processes such as cutting, folding, binding, or coating to prepare them for distribution or further use.