COLOR SEPARATIONS:

Hybrid Screens to eliminate Moiré

Inkjet printers have revolutionized the production of color separations for screen, flexo, and litho printing. Wasatch SoftRIP SP is the industry-leading solution for inkjet color separations.

A Wasatch Exclusive

The Precision Rosette/Stochastic Hybrid Screens feature in Wasatch SoftRIP SP eliminates the "fourth screen" or "yellow" moiré, allowing users to print yellows and flesh tones without worrying about moiré or changing screen angles. Prints made with these separations exhibit the rosette structure that print buyers expect, while using stochastic screening to eliminate moiré.

Euclidean Round

CMK

Euclidean Elipse 60-40

CMYK

The best–known of all printing moiré problems arises because of the need to add a fourth screen at a 15 degree angle after all possible 30 degree angles have been used by the CMK separations, as shown above. This moiré, which is familiar to all press people, is shown even more clearly by isolating two screens at 15 degrees to each other as illustrated below.

trickscreens_screensAt15

Since the invention of FM halftoning, it has become common in many high–end print shops to simply substitute an FM screen for the offending yellow plate, as shown below.

trickscreens_black.png

Black

trickscreens_cyan.png

Cyan

trickscreens_magenta.png

Magenta

trickscreens_yellow.png

Yellow

Prints made with these separations exhibit the rosette structure that print buyers expect, while using stochastic screening to completely eliminate the cause of most complaints regarding moiré. This well–proven method actually makes the moiré pattern shown above impossible to achieve.

It's Easy with Wasatch:

Wasatch SoftRIP SP makes these screen sets incredibly easy to set up. Special tools provide all the information you need to quickly configure a stochastic screen for the 15–degree plate. You can adjust the stochastic dot size both in terms of microns and of the lightest tonal value of the associated rosette screen that you can hold on press. A key to the power of this is the perfect "locked" rosette structure of Wasatch Precision Rosette Screens.