Tell me more about screen systems

Screen systems contain an optimal set of screening characteristics for a particular screening requirement. Predetermining the relationship among screen angles, screen rulings, and the screens to which these are assigned reduces the occurrence of screen artifacts.
 
Screen angles are calculated as in the above illustration.

Maxtone

This screen system forms a rosette among black, magenta, and cyan by screening these separations at equal rulings with nominal angles of 75°, 15°, and 135°. The yellow separation is screened at 0°, with a ruling slightly higher than the other separations to reduce moiré. In the default angle assignment, black, as the most dominant color, is screened at 135°.

This system is susceptible to moiré in smooth tints of two separation pairs: cyan-yellow (greens) and magenta-yellow (flesh tones). Angle swapping allows moiré susceptibility to be shifted from one of these separation pairs to the other. For applications with dominant flesh tones, putting magenta at 135° is recommended.

This system has been formulated for best performance on output devices to provide even, low-moiré flat tints, especially on large-format devices.

Maxtone Y30°

This screen system is identical to HQS Classic in all but its yellow screen. It forms a rosette among black, magenta, and cyan.

The yellow separation is screened at 30°, with a ruling slightly higher than the other separations. It avoids the 0° screen, which may cause interference problems in some flexography and silkscreen applications. In its default angle-to-color assignment, magenta-yellow moiré is eliminated, leaving the cyan-yellow separation pairs susceptible to moiré.

This system has been formulated for best performance on output devices to provide even, low-moiré flat tints, especially on large-format devices.

Maxtone Y60°

This screen system is identical to HQS Classic in all but its yellow screen. It forms a rosette among black, magenta, and cyan.

The yellow separation is screened at 60° with a ruling slightly higher than the other separations. It avoids the 0° screen, which may cause interference problems in some flexography and silkscreen applications. In its default angle-to-color assignment, cyan-yellow moiré is eliminated, leaving the magenta-yellow separation pairs susceptible to moiré.

This system has been formulated for best performance on output devices to provide even, low-moiré flat tints, especially on large-format devices.

Maxtone Y-fine

This screen system is identical to HQS Classic in all but its yellow screen. It forms a rosette among black, magenta, and cyan.

The yellow separation is screened at 0° with a ruling about 40% higher than the other separations. This raises the moiré frequency of yellow with all other separation pairs to the point where it is invisible at typical screen rulings for offset lithography. The increased yellow screen frequency may increase dot gain, requiring color-specific calibration to avoid a yellow cast in color reproduction.

Maxtone RT01 Y0K45

This historical screen system forms a square rosette among black, magenta, and cyan by screening these separations at slightly different rulings and nominal rational-tangent angles of approximately 18°, 45°, and 72°. The yellow separation is screened at 0° with a ruling slightly higher than the black separation.

This system is susceptible to moiré in smooth tints of olive-green color.

Maxtone RT04 Y45K45

This screen system provides an alternative to rosette-forming HQS screen systems. The rosette pattern is practically invisible at typical screen rulings for offset lithography.

Cyan and magenta separations are screened at equal rulings, with rational-tangent angles of approximately 18° and 72° respectively. Yellow and black are screened at 45°. The yellow ruling is about 10% below that of cyan and magenta, and the black ruling is about 33% higher. The differing dot gains resulting from these varied rulings may require color-specific calibration.

This screen system does not exhibit the moiré susceptibility of separation pairs found in the other screen systems.

The key separation (45° fine) can be used as an additional color in combination with the HQS screen systems.

Staccato

Staccato is a stochastic, or frequency-modulated (FM), screening solution that can be purchased as an option to Prinergy Evo software. The combination of Staccato and SQUAREspot thermal imaging technology gives you a level of control in the printing process that makes stochastic screening viable for routine presswork.

The demands stochastic screening places on time and equipment usually mean it is not a practical solution for everyday print production. It is difficult for many printers to deliver stochastic screening with conventional output devices because these devices do not offer the control required in the calibration, development, and platemaking processes. Staccato, however, makes FM screening a practical option for your routine presswork. You can also mix Staccato screens with conventional screens.

There are five screening patterns. You configure how Staccato screening patterns are applied to process and spot colors by mapping the color name to a screen angle via the options in the Calibration & Screening section of an output process template. If you do not map the color name to a screen angle, Prinergy Evo software by default applies the black angle to the color. You can change the default black angle via the list. Alternatively, you can choose to apply the available screen angles in a cyclical pattern by selecting the check box.

Screen Color

The Screen Color box and at Angle list allow you to:

• Set screening for colors other than the four process colors
• Swap the process color screens within screen systems
• Assign a screen for the default color, which is then used for any color that doesn't have its own screening value in the output process template or in the color database

The screen angles associated with each process color in the at Angle list vary, depending on the screen system and dot shape selected. See Tell me more about screen angles

At Angle

The Screen Color box and at Angle list allow you to:

• Set screening for colors other than the four process colors
• Swap the process color screens within screen systems
• Assign a screen for the default color, which is then used for any color that doesn't have its own screening value in the output process template or in the color database

The screen angles associated with each process color in the at Angle list vary, depending on the screen system and dot shape selected. See Tell me more about screen angles

Default Color

Enables you to select a default screen angle for all spot colors that you have not specified in the Screen Angles box with a Screening angle. You can select a default screen angle based on either the Cyan, Magenta, Yellow, or Black screen angles.

CycleSpots

Unmapped colors are mapped to screen angles in a cyclic fashion. For example, the first spot color is screened using the Cyan screen angle, the second using the Magenta screen angle, the third using the Yellow screen angle, the fourth using the Black screen angle, the fifth using the Cyan screen angle, and so on.

For more detailed information about Staccato screening, see the Staccato User Guide.