Offset or conventional printing is the oldest printing method and has been around for more than a century. Robert Barclay first employed it in 1875 when he patented the first rotary offset lithographic printing press.
It involves a mechanical process by which the design image is initially burnt onto an aluminum plate and then transferred onto a rubber “blanket” and finally onto the printing surface. When used together with the lithographic process that involves the repulsion of oil and water, the offset method employs a planographic image carrier on which the image to be printed gets ink from rollers while the non-printing area draws a film of water, keeping the non-printing areas ink-free.
This method of printing is commonly used in high volume commercial printing such as printing newspapers, magazines, and books because it provides accurate color control, variation, crisp, and professional looking printing.