A continuous-tone copy refers to an image with smooth tones and uninterrupted tones. This term is commonly used when discussing color illustrations, which are typically printed using a four-color process.
The primary purpose of continuous-tone copy is to represent an image with realism accurately. This is particularly crucial for images that will be reproduced in print, like photographs. Each color is separately printed as a different color separation when employing a four-color process. Any irregularities in these separations can become magnified during printing, resulting in an inaccurate reproduction.
Another advantage of continuous-tone copy is its ability to create visually appealing images. In a typical four-color process, thin lines of varying colors called halftone screens separate the colors. However, when printing without these screens, the colors blend seamlessly for a smoother appearance.
Generally speaking, continuous-tone copy refers to any image reproduced without dots or other markings. Typically associated with color illustrations utilizing the four-color process, it ensures realistic representation and can enhance visual appeal.
Continuous-tone copy allows smooth transitions from light to dark tones and avoids conspicuous lines in line art imagery. It plays a significant role in creating natural-looking illustrations—particularly those involving colors—which appear more harmonious compared to the sharpness and artificial feel produced by line art reproductions.
Moreover, this method mitigates posterization issues often present in line art reproduction, where unnatural banding occurs between different tones.