Sharp, bright and clean
Fully optimizing high frequency images in print
Continuous tone from HDS screened images
Harlequin Dispersed Screening (HDS)
For outstanding print results in Offset Litho and High Resolution Inkjet applications you need Global Graphic’s patented Harlequin Dispersed Screening (HDS).
HDS Stochastic screening resolves many of the quality issues, such as moiré, mid- tone jump and banding that conventional screening methods have failed to answer. Legacy problems usually experienced with FM (Frequency Modulated) technologies such as graininess, dot gain, dot loss, and system slowness have been solved by the combined application of technology, including HDS, with recent advances in the fidelity of digital output and printing processes.
HDS enables reproduction with greater sharpness even at relatively low scanner resolutions and is ideal for reproducing subjects which are susceptible to moiré and where detailed reproduction is required.
Harlequin Dispersed Screening is Global Graphics’ patented, stochastic screening system designed for low-resolution output devices. HDS creates reproductions with enhanced sharpness over conventional screening methods and provides freedom from both cross screen and object moirés. With HDS, Global Graphics has tackled many of the shortcomings experienced in other stochastic screening techniques and provides a robust, high quality screening solution for a variety of printing applications.
- Unique Screen Structure:
- Although the screen structure of HDS contains a random component, there remains an underlying ordered, though dispersed, structure. The dispersed screens produce structures with a high perimeter to area ratio, enabling reproduction with greater sharpness even at relatively low scanner resolutions. HDS is ideal for reproducing subjects which are susceptible to moiré and where detailed reproduction is required.
- Speed and Performance:
- Most FM and stochastic screening methods typically reduce the speed and performance of the RIP. HDS can be integrated into the Harlequin RIP without compromising performance; high speed and performance gains over other FM screening methods are achievable whilst retaining the ability to produce high-quality output.
- Smart FM Dot Dispersal and Higher Quality Images:
- HDS eliminates the grainy highlight effect experienced with some FM screening methods particularly apparent in smooth areas of continuous tone pictures, flat tints, and vignettes. The HDS dispersed but still clustered approach dramatically improves the printability, stability, quality and predictability of the printing process. Because individual spots do not randomly cluster into structures with odd sizes and shapes, graininess is reduced compared with other FM screening methods.
The HDS Family
HDS includes a family of screens, customized for different reproduction processes and output device capabilities. HDS includes standard four colorant screens for use with the standard CMYK process colors and spot inks, as well as variants developed for hexachrome and photoink devices. HDS is also available in the following five varieties of dot structures or “settings” facilitating its compatibility with a range of output devices.
|HDS Fine: HDS Fine produces extremely smooth grain-free results and has the finest structure of any HDS setting. It is intended for use with high quality output devices capable of recording single isolated laser spots on separations.|
|HDS Medium: HDS Medium offers a slightly larger dot structure in the midtone range. It may be used in intermediate commercial and publications printing, either sheetfed or web.|
|HDS Coarse: HDS Coarse makes use of somewhat larger structures to increase printability and is best selected on presses which cannot hold very fine detail such as in high speed web printing.|
|HDS Super Coarse: HDS Super Coarse uses a larger structure to increase printability and the capability to retain highlighted areas of an image. It is suitable for use on mid- to low-range imagesetters or platesetters with resolutions between 1000 and 1600 dpi.|
|HDS Super Fine: In addition to the settings above which are meant for use with various types of imagesetters and CtP devices, Global Graphics has developed a screening solution for low resolution output devices which delivers high quality output without compromising speed.|