Thinking inside
the offset dot
Everyone agrees that flexo printing technology, especially the UV-cured variety, has seen remarkable improvements in quality in recent years. Nevertheless, offset remains the process to beat and it does not appear to be standing still, thanks largely to incremental improvements with screening technologies. An example is Concentric Screening technology from Artwork Systems Group. The company reports positive customer reviews for the system which is said to address the fundamental problem of reducing dot gain.
The new halftone dot technology divides the conventional round dot into thin concentric rings that limit ink film thickness on the offset plate. This is claimed to provide greater stability on the press and give increased color saturation. It also allows finer screen rulings without the traditional problems of mottle, dot gain and the risk of variability. Concentric Screening is said to have proven its effectiveness in all offset printing segments, including packaging, and is available with the Nexus and Odystar workflows.
Mark Samworth, vice president of technology, said the basic geometry of the conventional halftone dot has hardly changed since the inception of offset-litho around the late 19th century. “While every external dot shape has been attempted, no change to internal shape had ever been tried. The internal shape on all dots has been ‘solid’. Concentric Screening is the first halftone dot that uses a different internal shape. It’s the world’s first non-solid halftone dot.”