Screening

For over a hundred years the printing and publishing industry has attempted to capture the quality of continuous tone images, such as photographs, in print. This has been achieved through the use of screening methods that convert images into dots for subsequent reproduction by a printing process. As pre-press and printing technologies have changed, screening techniques have been refined to make better use of these new technologies.

Patented screening technology

Global Graphics holds many patents for its technology. One in widespread usage is Harlequin Dispersed Screening, a patented second generation stochastic screening system that addresses many of the deficiencies in other stochastic screening techniques.

Multi-bit screening

For digital printing applications, multi-bit screening allows you to achieve near photographic quality and allows devices at relatively low resolutions to produce very smooth images, graduations and flat tints.

Conventional halftone screening technology (AM screening)

This form of screening breaks a continuous tone image into a series of dots. The dot pattern is controlled by changing the screen ruling. It’s very widely used in office, traditional and digital production printing, but brings with it common quality concerns such as moiré, problems with tone gradation and dot gain and loss of highlight detail. These can be addressed with the Harlequin Screening Library

Stochastic screening

Stochastic screening was developed to solve the quality issues encountered with AM screening such as moiré and is also used for office, traditional and digital production printing and wide format applications The very small dots used produce significantly better quality images than conventional screening. However, you still need to select a good quality stochastic screening product such as the patented Harlequin Dispersed Screening™ to obtain the best results.

Error-diffusion screening

Error-diffusion screening, or EDS, was developed primarily for proofing and wide format applications at relatively low resolution. The screen is created programmatically as the page is rendered, allowing it to respond to the specifics of the contents of each page. EDS can produce very good results under the right circumstances, but is too slow for some applications, and can suffer from quality issues such as tear-away or mottle in flat tones.

Cross-Modulated Screening or hybrid screening

Cross-modulated screening aims to take advantage of the best aspects of both AM and FM screening and gives smooth, noise-free flat tints while retaining fine detail in highlights and shadows. It allows you to print screens at a higher line ruling than would normally be considered reliable, produces pin-sharp images and helps overcome common printing imperfections like visible rosettes and moiré. It is suitable for office, traditional and digital production printing and wide format applications.

Custom screening

Whichever RIP supplier you choose, there may be some cases where you’d like to use your own screens in your system, whether they are supplied as pre-generated caches or are created programmatically during rendering. And you need to be sure that you can secure your IP appropriately for distribution.