contone

A contone image displays a continuous gradation of tones from the brightest highlights to the deepest shadows, without the dot pattern or stippling that characterizes halftone reproduction. In printing, this means the artwork contains genuine intermediate greys and colors rather than optical illusions created by screens of dots at varying sizes or spacing. Photography, airbrush art, and digital paintings are naturally contone; once they enter traditional offset or letterpress workflows, they must be screened to halftone form because those presses cannot hold continuous tone.

Contone originals present a capture and workflow problem for conventional offset printing. A camera or scanner reads the full tonal range, but the press can only deposit ink or leave paper bare. The solution, since the early twentieth century, has been the halftone screen, a fine grid of lines or dots that breaks the image into printable units. The fineness of the screen (measured in lines per inch, typically 150 to 300 lpi in commercial work) determines whether the halftone pattern is visible to the naked eye. A poorly chosen screen can introduce moiré patterns or lose detail in shadows and highlights.

Digital workflows have blurred the contone boundary. High-resolution inkjet and modern photographic printing processes can approximate contone output directly, laying down variable dot sizes or ink densities without the periodic screen structure. Laser and electrophotographic presses use stochastic screening, random dot placement that mimics continuous tone more closely than traditional line screens. These technologies have made contone-like results accessible without film separation and screening, though the underlying technology still quantizes tone into discrete levels.

The term contone itself derives from continuous tone, emphasizing the absence of discrete steps or patterns. In prepress, contone originals are often described as flat or continuous art to distinguish them from line art, which contains only solid black and white with no intermediate values. The distinction matters for reproduction method selection, scanning resolution, and output device capability. A photograph is inherently contone; a logo is line art.

In practice, the choice between preserving contone quality and accepting halftone screening depends on budget, substrate, and press technology. Fine art reproductions and high-end packaging often justify stochastic or inkjet methods to avoid visible dot structure. Mass-production magazine and newspaper work accepts conventional screening as a known trade-off between cost and fidelity. Understanding what contone is helps identify where tone loss and pattern artifacts enter the reproduction chain.