The fundamentals of Indigo's Digital Offset Color printing process and how it rivals mechanical offset printing

At DRUPA 2000, Indigo unveiled a new generation of ultra-high-speed Digital Offset Color presses, both sheetfed and web. The seven newly-introduced presses include the industry's fastest digital color printing products. "Digital Offset Color" is a process combining Indigo's unique electrically-responsive ink, "ElectroInk", with a specially-developed thermal transfer process and a fast color switching technique. These are complemented by an ultra-high performance multi-beam laser scanner and unique image processing software. Pumping through the heart of Indigo's digital presses is its propriety ElectroInk. ElectroInk enables these liquid electrophotographic printing presses to deliver prints of true offset quality. Only one to two microns in size, charged ElectroInk particles form highly defined characters, line work and halftone dot patterns. The "look and feel" of offset is achieved by a combination of ElectroInk's high saturation and extended color gamut and its unique ability to replicate the surface gloss of the underlying paper stock. The very small particles form extremely thin ink layers less than one micron thick - enabling both high quality and low cost. Latent image formation, "Binary Ink Development", and thermal offset transfer are discussed.