"Screening" Option for Prinect MetaDimension

"Screen System" list box

Note: The screen systems available for selection depend on the connected imagesetter and on the rendering engine used (Prinect Renderer or Prinect MetaDimension). For that reason, not all of the screen systems presented are available for all constellations.

Note: The following tips are valid for "Document Controlled Screening", "Hybrid Screening", "Stochastic Screening starter", "Stochastic Screening medium", "Stochastic Screening fine", "Stochastic Screening super fine", "Stochastic Screening II medium", "Stochastic Screening II fine", "Satin medium" and "Satin fine" screen systems:

•"Document Controlled Screening"

The "Document Controlled Screening" system is suitable for the output of dummy samples. The system automatically switches to "Document Controlled Screening" for screen frequencies up to 15 lines per centimeter. In this case it is assumed that a dummy sample is being output, not a quality screening. "Document Controlled Screening" is the screening method that is the least accurate. The technique is not recommended for multi-color reproductions (color separations).

The screen frequency (5-700 lines/inch) is entered manually for the "Document Controlled Screening" system. The second input box, "Line Frequency", is activated for this purpose.

•"Hybrid Screening"

The frequency and the dot size are relevant for amplitude-modulated "Hybrid Screening". The "Line Frequency" and "Feature Size" list boxes are enabled.

•"Stochastic Screening starter", "Stochastic Screening medium", "Stochastic Screening fine", "Stochastic Screening super fine", Stochastic Screening II medium", "Stochastic Screening II fine":

The dot size is important for frequency-modulated "Stochastic Screening". The "Feature Size" list box is enabled and the "Line Frequency" boxes disabled.

•"Satin medium", "Satin fine" and "Satin super fine"

The dot size is important for the "Satin" frequency-modulated screening method. The "Feature Size" list box is enabled and the "Line Frequency" boxes disabled.

•You can also set the dot size for "IS Classic" like for "Hybrid Screening" if the "Hybrid Screening" license option is enabled.

"Dot Shape" list box

In this list box, you set the screen dot shape that will be used for the screen system you selected.

"Resolution" parameter

This is where you set the imagesetter resolution (in dpi or pixels/cm) for the screen that will be cre­ated.

"Frequency" parameter

In these list boxes, you can select one of the screen frequencies (in lines/inch or lines/cm) that are presented for the selected screen system. There is a special frequency box for "Document controlled screening" where you can type in a screen frequency.

"Feature Size" parameter

The feature size (dot size) is relevant for frequency-modulated screens (see note on this above).

Note: The "Feature Size" parameter is not a calibration parameter. This means that calibra­tion data records cannot be differentiated solely on the basis of different dot sizes. This affects calibration of the "Hybrid Screening" and "IS Classic" screen systems if these are selected in output sequences with different dot sizes but otherwise the same parameters. You must create different calibration groups for linearization and for process calibration if you are going to use different calibrations whose only difference is their dot sizes. These cal­ibration groups must contain the calibration data records that are required for the various dot sizes.

Options for object screening

The Acrobat plug-in "Heidelberg Screening Selector" lets you assign different screen settings to single objects within one PDF document. The "Ignore Object screening information" and "Use Object Scree­ning Information" options define how such object screening parameters will be handled during out­put. The "Screening Selector" tool is part of "Prinect PDF Toolbox" that is included in the shipment of the Prinect software and is normally installed together with the Prinect Cockpit.

"Ignore Object screening information"

When you enable this option and a document has objects with different screen settings, this screen­ing information is ignored, and the screen settings defined in the sequence are used.

"Use Object Screening Information"

The object screen settings defined in the documents are applied when you enable this option.

"Optimize Step and Repeat" option

"Step and Repeat" is a technique that copies and positions at the same time.

This option is designed for print jobs that have several identical pages placed on one sheet (copies). The aim of step-and-repeat optimization is to interpret each of the objects that are repeated just once to shorten processing time.

You enable the function with this option. Then each of the objects that are repeated in jobs that have copies is interpreted just once.

"Synchronize screening for each page" option

When this option is enabled, the screen is synchronized at every multiple object (on every page). This option is required for packaging printing and for security printing (e.g. bank notes). The screen tran­sitions can be seen in the printed result if the single pages abut each other.

The screen always starts at the top left corner of the sheet if the "Synchronize screening for each page" option is disabled, and there is no renewed synchronization within the sheet. This is the same as processing without step-and-repeat optimization.

Step-and-repeat optimization is not applied even if the option is enabled if you have one of the follo­wing conditions:

•The multiple pages are rotated and rotation is not a multiple of 90° (e.g. 1° to offset errors during cutting).

•The pages are split for proofing because the "Split Document" option is enabled.

Angle substitution settings

In the top right part of the "Screening" window, you can define settings for angle substitution for amplitude-modulated screen systems.

With the help of the angle substitution functionality, you can assign new screen angles to the process colors (cyan, magenta, yellow and black) and to spot colors. In other words, the angles set in the job documents are changed to new angles that you define in this section when they are output. In addi­tion, you can assign screen angles to spot colors.

The colors currently assigned to the angles display in the Angles (*) box.

Assign angles

Each of the four process colors (cyan, magenta, yellow and black) and the spot colors have their own list box with the four process colors. To assign another angle to a color, select the process color that is linked to the angle you want in the list box.

Example: You want to assign a different angle to magenta. The default system angle for magenta is 45°. If you select "Cyan" in the list box beside "Magenta", magenta is output using the screen angle for cyan, in other words at 165°. This angle displays in the "Angle (*)" box beside the list box.

To prevent different process colors from being output with the same screen angle, you must assign other screen angles accordingly so that each color is assigned its own screen angle.

A comparison with the default screen angle of the selected color that is shown in the "Angles (*)" box makes it easy for you to reconstruct which substitute angle is set.

"Cyclic angle substitution" options

You can also assign different screen angles to spot colors with this function. The idea behind this is for you to be able to assign as many as four screen angles, depending on the number of spot colors you have. The enabled angles are then assigned cyclically to the spot colors.

If you enable just one check box, all the spot colors in the documents will be assigned to the screen angle opposite. If you enable several check boxes, the spot colors will be assigned in turn to the enabled screen angles. Spot colors will be assigned cyclically to the screen angles if there are more spot colors than enabled screen angles. For example, if you have five spot colors and all check boxes are enabled, the angles for cyan, magenta, yellow and black are assigned to the first four spot colors. The angle for "Cyan" is assigned again to the fifth spot color, etc.

Note: Spot colors which only differ by the ending in the name are treated as one color. Example: No difference is made between the colors "PANTONE 165 C" (coated) and "PAN­TONE 165 U" (uncoated) and they are assigned to the same angle.

Note: Take note of the following items when you use the 'assign spot color to screen angle' function:

·The names of the spot colors are irrelevant in the assignment of angles. The angles are assigned if the spot colors occur in the document.

·Process colors must not be set for angle substitution if duotone and tritone images will be processed together with process colors.

·Only the cyan and magenta angles may be used for spot colors if duotone and tritone images that have black will be processed!

·Do not use any fine screens in conjunction with the spot color-to-angle assignment. This can cause problems with yellow and black.

·Process calibration may not be correct if you use the 'assign spot color to angle' func­tion.

·The angle defaults for spot colors are also affected by the assignment of angles. The default angle is 45° (magenta).

"Override Frequencies from Document" option

The screen frequency in the edited document (set in the DTP application) is overwritten by the screen frequency set in the output sequence.

"Use Frequencies from Document" option

The screen frequency in the edited document (set in the DTP application) is used.

Generally, it is advisable to use the screen frequency of the output sequence as this gives you a reli­able output.