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• Disable:
RIP output is the same as Acrobat display
• Treat gray as black:
This option is to be used in a special case: Objects using the De-
vice gray Colorspace always knockout the underlaying separa-
tions and thus ignore the overprint settings. Treating these
objects as Black will force them to recognize the overprints.
• Page Box popup (PDF Only)
This popup chooses which one of the five PDF page boxes (Me-
dia, Crop, Bleed, Trim and Art) will define the boundary of the job
to be ripped. See the PDF reference for an explanation of these
page boxes.
9.2.6 Advanced
• Enable PS level 3
By default, the interpreter supports PostScript 3 functionality, in-
cluding smooth shading. There may, however be situations
where it may be appropriate to disable this functionality and only
support level 2 PostScript. This is accomplished by disabling the
Enable PS Level 3 box. This approach can be useful if problems
with PostScript 3 files are encountered, but only where the Post-
Script checks the language of the interpreter and offers an alter-
native implementation. In some cases, this will not be possible
and the job will either fail with a PostScript error (for example on
a PostScript 3 operator such as shfill) or will produce a page
showing a diagnostic message, such as: “This job requires Post-
Script 3”. Where a PostScript level 2 alternative implementation
is available, there is likely to be a performance penalty.
• Log all output
The PostScript language has the capability to output information
to a file using operators such as == and Pstack. Although not
particularly useful in an operating environment, this mechanism is
very valuable as a debugging aid. By checking the Log All Output
check box, any PostScript code that results in output to stdout
will be included in the interpreter log file.
• Dump buffer on error
If this box is checked as recommended, in the event of a Post-
Script error a detailed listing of PostScript stacks will be output to
the Interpreter log file. This may be useful for diagnosing Post-
Script problems. When a PostScript error occurs, the Interpreter
icon in the job edit window will show a red triangle which when
clicked will open the Job Errors window. This will indicate that the
error occurred in the Interpreter and it will report the error code
(e.g. undefined) and the Offending Command
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This information by itself may be sufficient to diagnose the fault,
but if not the extended error handler (provided by the ini file called
exterror.ini) will cause the execution and operand stacks to be
dumped to the Interpreter log file. This log file can be viewed by
selecting interpreter from the Modules window and pressing the
View Log button.
However if this information is still not sufficient to locate the prob-
lem, it is sometimes useful to be able to locate the exact point in
the PostScript file where the error occurred. This is made possi-
ble by checking the Dump Buffer on Error option in the Interpreter
window. This has the effect of generating a dump of the Post-
Script code just before, and after the point where the error oc-
curred. As this may result in the size of the Interpreter log
exceeding the buffer size, used to display log files, it may be nec-
essary to view the log file on the server computer. (e.g. using
Notepad).
• Default Resolution
The default resolution for the interpreter on the workflow would
normally be the same as the resolution at which the Assembler
makes screened separations. In the case of an Avantra this could
be 2400 dpi. This value will be used by any PostScript algorithms
that require the device resolution to generate appropriately
scaled objects. PostScript is generally device independent, but
there are situations where the output needs to be optimized for
the output resolution.
Some well known situations are the processing of hairlines and
fine patterns, but also barcodes created with special applications
may require the resolution during interpretation to avoid rounding
errors because of a different output resolution.
When there are two output devices in one workflow, having dif-
ferent output resolutions, the ripping resolution cannot be opti-
mized for both. Choosing the higher resolution will not
compromise the quality of the lower res. devices (proofers). The
default value in the interpreter is 3810 lpi, which is in most cases
sufficiently high.
• Default ruling
Besides the default resolution, now you can also set the default
ruling, in lpi.
• Preps Layout Place
If this option is on, a plate will be generated, containing marks
based on the comments inserted by Preps. It is based on an init
file which was used with earlier versions of Nexus.
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9.3. Merge OPPO Files
Merge is used to merge separated OPPO files made by the inter-
preter into composite form, in preparation for trapping and or proof-
ing. Therefore, the merger is part of almost all workflows. Only basic
and imposition workflows, containing no composite proof, may ex-
clude the merger.
When separated PostScript is processed by the interpreter an
OPPO file is generated for each separation. On a PSTI workflow (or
any one which requires a composite file to be created, including
DCS) it is necessary for these OPPO files to be merged together into
a single OPPO file.
Where a PostScript object has been defined in more than one color,
the identical OPPO object may be present in more than one of the
OPPO files created by the interpreter. The OPPO merger processes
all of the separated OPPO files in parallel and attempts to combine
otherwise identical OPPO objects. This is normally successful and
typical results in a composite OPPO file that is only slightly larger in
size than a single separated OPPO file.
9.3.1 Overprinted Strokes
Sometimes, objects (such as trap areas) are defined to overprint by
creating them in just one color. The merger is capable of detecting
such objects and provides the opportunity to remove them or cause
them to knock out underlying objects, depending on the Overprint-
ed Strokes popup select. However, this popup should be used with
great care, because it can sometimes result in the unwanted re-
moval of objects (such as Quark mixed color blends). The default
setting is to leave the original specifications (no action).
By selecting the remove option, unwanted traps that have been
generated by applications, such as Adobe Illustrator and that would
otherwise interfere with the raster trapping of PSTI, will be deleted.
An example of this is shown below, where some light colored object
has been trapped in a darker background. By removing the stroke,
the original object outline is restored. The last image shows the re-
sult of a knockout which may be more appropriate than removing
the stroke in some circumstances.
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9.3.2 Buffer limit
When attempting to merge very complex OPPO files, it is possible
for the Merger to fail to merge every object completely. The merger
activity will finish, processing of the resulting merged OPPO file will
continue and this will not necessarily result in incorrect output.
However, under these circumstances, it may be necessary to in-
crease the size of the object buffer in the activity editor to more than
the default value of 10000 objects. The merger activity should then
be retried.
9.3.3 Identify Blends
When setting up a TIFF/IT Out workflow to create TIFF/IT files with
a LW part, this option has to be checked in the Merger. In all other
cases, the option can be left unchecked. The option detects vi-
gnettes and shadings that do not use the standard PS Level3 shad-
ing operators and converts them into smooth shadings. If you don’t
identify the blend in the merger and you make a TIFF/IT with an LW
part, unrecognized blends will be a part of the LW. This can cause
the number of colors in the LW part to reach the limit. If you identify
the blend, it will be put in the CT part, leaving the LW part un-
changed.
9.3.4 Fail on empty page
If this option is enabled, the Merger will fail if it encounters complete-
ly empty pages.
9.3.5 Output
When editing the merger activity in the workflow edit window, the
Output button may be used to configure the naming of the merged
OPPO file, using the File Naming Template. See 3.6. File Naming
Template on page 132. This may be useful on Vector Page work-
flows.
9.3.6 Running a job through
the merger
When a job is run on a workflow that contains the merger, editing
the merge activity in the job edit window will result in a larger edit
merge window, with a box containing a scrollable list of color defi-
nitions for all separations comprising the page. For each color in the
list, percentage values are shown for each of the process colors.
This color combination defines how the color will trap, proof and
otherwise be displayed.
The CMYK equivalents of
PANTONE™ colors are
stored in a file in the RIP di-
rectory called Color_Lib.
Each line of this file contains
5 fields, the first is the color
name (with spaces changed
to underscores) and the re-
maining ones defined the
fractional components of
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Cyan Magenta, Yellow and Black respectively. When colors are
looked up in this file, the CV entry is used when there is no match
on CVU, CVS etc.
If the color is not defined in the Color_Lib file, a definition for it may
be present in the PostScript file itself, in the form of CMYK Custom
Color comments, in which case these values will be used.
If no definition for the color is available, the merging process will be
put into a held state (i.e. spool icon shown in the job list), providing
the operator with the opportunity to specify how the color is to be
proofed and trapped. This is done by editing the merger activity in
the job list.
When this is done, the Select Color window will open and the ap-
propriate values for Cyan, Magenta, Yellow and Black defined, ei-
ther directly into the text boxes or by using the slider bars. An
approximate representation of how the color will appear on the
proof is given in the Example patch at the top of the window. The
colors that would be produced by each slider bar are also shown.
When the desired color has been specified, the OK button should
be pressed. An option will exist at this time to save this color in a
supplementary definition file, called UserColor_Lib. If a color defini-
tion cannot be found in the Color_Lib file, this file will be searched
before check for a PostScript comment definition
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9.4. Assemble Separation
Assemble separation is used to generate high resolution separation
files in the format required for output, which is typically screened
TIFF.
The dialog, which is the same for all Assembler activities, adjusts to
the options already selected, e.g. when changing the Format option
from TIFF to EPS, the button next to it (and the corresponding dia-
log) will change from “TIFF Options” to “EPS options”.
9.4.1 General
The General settings at the top of the dialog contain selection of De-
vice and its resolution, Template settings, File Format and file format
dependent settings (TIFF/EPS/PDF settings), More Options and Ex-
clude/Include Colors. The output will be 1bit unless the Screening
is set to “Unscreened”
• Device / Resolution
The Device popup is used to select the target device for the data.
The popup references the device context file which contains all
information on the different output engines. As explained earlier,
this context file may be edited to adapt the device list to the cus-
tomers situation.
If a device is selected from the list through the popup, the reso-
lution popup will be adapted so that only valid resolutions will be
selectable. If the desired device is not shown, a new device may
be added tho the device file. If no Device is selected, the required
resolution should be entered in the text field.
• Edit Template
The Edit Template allows to define the name to be used for the
output files. See 3.6. File Naming Template on page 132
• Format
The Format menu allows to set the file format for the output files:
TIFF, EPS, PDF, Scitex CT or Scitex Line work. Depending on the
settings here, other options become available
9.4.2 TIFF Options
• Compression Mode
The TIFF options allow to set Compression Mode. This would
normally be set to Packbits for TIFF (for optimal performance) and
Flate for PDF and EPS. If Flate causes problems with EPS, Pack-
bits can be used. CCITT G4 compression can result in smaller
files but there is a performance penalty to be paid when com-
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pressing and decompressing these files, which could cause
problems when driving devices directly. None will result in very
large files, but can be useful when diagnosing problems.
• Tile Size
The Tile Size should be set to a value other than Don’t Tile only
when it is known to be advantageous for the receiving device, in
which case it would typically be set to 2048.
• TIFF Strips
The recommended value for this option is 64K or 512K. A TIFF
file is always forwarded to the imagesetter in packages of a cer-
tain size. With this option you can choose the size of a package.
You can always use the recommended value, but some devices
will require a specific package size (e.g. Aabach and HelioKlis-
choGraph). In that case, the size can now be adjusted.
• Metric Units
If the Metric box is checked, all measurements for TIFF tags will
be in millimeters rather than the default unit of inches. This may
be appropriate for devices that require metric resolution (e.g.
some Fuji imagesetters). Some devices (e.g. ECRM) may not ac-
cept metric units.
• Include Color Tag
If the Include Color Tag option is on, a tag is generated, contain-
ing the name tag for the specific separation. Some proofers, such
as the Creo Spectrum, can use this tag to map the TIFF to the
correct separation. Normally, TIFF readers which don't under-
stand this tag should ignore it, however if it errors on this tag, the
option should be switched off.
9.4.3 EPS Options
• Compression Mode
See 9.4.2 TIFF Options on page 306
• Binary
By default EPS Output will be binary. If binary codes cause prob-
lems e.g. on a proofer’s RIP this may be unchecked to generate
ASCII code. a check to set to Binary data (instead of Ascii).
• Allow Scaling
The Allow Scaling option is typical for DCS output files. If it is not
checked, then any attempt to place this DCS file in an application
and scale it before printing will result in failure. This is intended pri-
marily to prevent the inadvertent scaling of screened DCS files.
Scaling of these DCS files would result in distorted screening.
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If the “Allow scaling” box is *not* checked, then Nexus puts some
PostScript code into the DCS sub, which will cause a PostScript
error if the file gets scaled in the re-rip process. If the box is
checked, then this code is not included in the DCS.
As a consequence this option should always be unchecked when
creating 1 bit depth DCS sub files. When creating 8 bit depth un-
screened DCS files, this option should be checked to allow trans-
formations in applications.
• Include %%Page Comments
Comments allows a PS comment, placing information about ev-
ery page of a multipage file in the PostScript file. As this is a sep-
arated output, this comment can be useful. Using this function or
not depends on the system that will process the resulting PS file,
and its ability to handle the page comments.
9.4.4 PDF Options
• Compression Mode
See 9.4.2 TIFF Options on page 306
• Tag ICC Profile
The Tag ICC Profile check allows the user to include ICC Profiles
in the PDF file.
9.4.5 Scitex LW Options
• Round metric page dimensions
This option will round off the page dimensions to the closest in-
teger. This can be used if the device you’re sending the Scitex
LW doesn’t support decimals in the page dimensions.
9.4.6 More Options
• Polarity
The polarity should be set as required for the final output. If both
positive and negative output are required, the option should be
left unlocked so that the control is available as PPD option. It
should be kept in mind that reversing the polarity is possible in dif-
ferent locations. The input file may have been printed negative,
but also the imagesetter may have an option to change the po-
larity. Where a combination of two negatives has been made, the
final output will be positive again.
• Orientation
The orientation is primarily a definition of the scan direction of the
output device, it reflects the physical construction of the device.
By convention, the page width is the film width, and the fast scan
direction is the film feed direction. On a drum device for example,
the orientation would normally be set to 90º or 270º, where the
default is 90º and this depends on how the image has to be ori-
ented with respect to punching. A Capstan device would normal-
ly have an orientation of 0º or 180º. As the orientation is
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predefined in the device list as well, it will change automatically
when selecting the output device. This device rotation should not
rotate screen angles.
• Black overprint
If set to No, Black line work objects will knockout the underlying
objects.
It should be set to Yes to force any line work object that is defined
to be 100% Black to overprint underlying process colors. Note
that this is only appropriate on an non-PSTI workflow. If black
overprint is required on a PSTI workflow, it must be defined in the
PSTI assembler activity (band to PSTI), e.g. for an autotrap work-
flow.
When set to Yes + White KnockOut, a white background of a
QuarkXPress EPS will be forced to overprint.
• Interpolate
This option is only applicable a 1 bit depth file. It can be checked
for higher quality output, however, there is a significant perfor-
mance penalty associated with this and this box is therefore de-
fault unchecked and left like this. The main area of concern
relates to image data, which is typically stored at lower than the
final output resolution. On a PSTI workflow, the CT data may al-
ready have been interpolated (as is automatic in Platinum mode)
but CT pixels will typically still be larger than output pixels, and
without interpolation, the edges of these pixels may result in
clipped screen dots as shown. The 1 bit TIFF on the right uses
interpolation.
• User mirror
This option reflects the scanning direction of the output device. It
is set according to the laser spin direction in the imagesetter, and
is, by default, unchecked for Agfa imagesetters. It will not result
in an image inversion on final output or flipping of screen angles
on film.
• Scale image by
Allows the user to scale the image during the assembly of the
separations, both in fast scan and slow scan direction.
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• Scale page as well
If unchecked only the contents of the page will be scaled (e.g. for
distortion purposes) If checked the page will be scaled complete-
ly.
• Advanced options
• Memory
The optimal memory allocation can be specified by entering an
appropriate value in the Max Memory Field in the window shown
on the right. This memory can be set independently for all assem-
bler activities (i.e. band, proof, link, separations).
• Pad Pixels and Pad Lines
These options should in almost all cases be left unchecked. They
may need to be checked for devices where the bitmap files are
required to have dimensions that are a multiple of 32 in width
and/or depth respectively. (e.g. when driving the Celix imageset-
ters via the Saturn import option because the number of scan
lines in a TIFF must be an exact multiple of 32) In Nexus, padding
to 8 pixels is supported automatically by the Agfa driver, so
checking Pad Pixels is not necessary anymore for Agfa devices.
It should also be noted that when TIFF files are prepared for the
Stitcher, they should not be padded. Although when stitching
TIFF files, the stitcher will byte align the images in any case.
• Transparent PSTI
This option defines how the assembler will place PSTIs in a Link
workflow. If the option is on, the PSTIs will be placed transparent
(where 0% paint is found, transparency will be applied), or, if the
options is off, PSTIs placed by their link will knock out everything
underneath.
• Legacy Bounding Box Handling
This option affects activities that make link files. In older versions
of Nexus, the image was not always correctly placed relative to
the origin, when the input job was for example a PDF with a Trim
Box whose origin was not at (0, 0). This is corrected in Nexus 8.1.
However, some users may be accustomed to correcting for this
at the Step and Repeat stage by applying an offset to the link file,
and may not want to change their workflow. In that case, the user
should check the option for legacy behavior.
Documents you may be interested
Documents you may be interested
