Imagesetters

An imagesetter is a high-resolution output device used in the graphic arts industry to produce images and text for printing. It exposes photographic film or paper with digital information, creating negatives or positives that are then used to make printing plates. Imagesetters replaced older phototypesetting machines and were themselves largely superseded by computer-to-plate (CTP) and computer-to-press (CTP) technologies.

The process typically involved a computer sending page layout data to the imagesetter. Inside the device, a laser or other light source would precisely expose the photosensitive material according to the digital data. This resulted in extremely sharp and accurate rendering of typefaces and graphics. Different types of imagesetters existed, varying in their resolution, speed, and the type of output material they used. Early models used continuous tone film, while later ones were capable of halftoning for commercial printing.

The primary advantage of imagesetters was their ability to produce high-quality output directly from digital files, offering greater precision and speed than previous manual methods. This was crucial for professional printing, where fine detail and color accuracy are paramount. Although largely obsolete for mainstream professional printing, the principles behind imagesetters laid the groundwork for modern digital prepress workflows.