ZePrA | PantoneLive EN

PantoneLIVE

Access PantoneLIVE libraries in ZePrA

Access PantoneLIVE libraries in ZePrA

PantoneLIVE® by X-Rite is a cloud-based solution for the digital storage of spectral spot colors. This applies both for Pantone Guides, paper-dependent, so-called ‘Dependent Standards’, as well as specific color libraries of brand owners.

Note: The use of PantoneLIVE requires a license for both the spot color module of ZePrA as well as a PantoneLIVE Production license from X-Rite. Activate your licenses in your My X-Rite account for use in ZePrA. See below for more details on the activation process.

Importing PantoneLIVE libraries

To import PantoneLIVE spot colors from the cloud into ZePrA, proceed as follows:

  1. Select Spot Color Libraries from the sidebar and click on PantoneLIVE.

  2. In the Login section you can either login using the User Name registered with Pantone or your e-mail address and your Password.

    Note: The login requires an active Internet connection and an activated PantoneLIVE license for ZePrA.
  3. If your company uses a proxy server you can enter the required proxy settings under Proxy before logging in.

    Setting proxy server for PantoneLIVE

  4. Your libraries will be displayed after successfully logging in.
  5. Select the libraries to import and use in ZePrA by enabling the corresponding check boxes. Then click Update. The spot colors will be downloaded from the cloud while the progress is shown in the lower part of the window under Status. Imported libraries are marked as up to date while libraries which have not been imported are marked as not used.
    Note: Depending on the number of selected spot colors and the speed of your internet connection this may take some time. The dialog cannot be closed during download.
  6. Once the selected libraries have been downloaded, you can close the dialog. Your PantoneLIVE libraries are now displayed under Libraries in the Manage Spot Color Libraries dialog and can easily be distinguished from other libraries by the Pantone icon.
Characteristics and use of PantoneLIVE libraries
  • PantoneLIVE libraries can only be used in ZePrA while you are logged into PantoneLIVE. Once logged out, the libraries can no longer be used.
  • As long as ZePrA is connected to the internet and you are logged into PantoneLIVE, imported PantoneLIVE libraries can be used without limitation.
  • If you have not logged off from PantoneLIVE but the internet connection is interrupted, already imported PantoneLIVE libraries can be used until the expiration date. Typically, this is for one month. The remaining days are shown in the Information column. However, it is recommended to log in again as soon as possible to be informed about potential color updates or to prevent error messages because the libraries are not available.
  • The revision number of PantoneLIVE libraries is displayed in the column Revision of the PantoneLIVE dialog and for already imported libraries in the column Information of the Manage Spot Color Libraries dialog. Additionally, the PantoneLIVE dialog indicates the Brand Owner and the column Dependent Standard Code shows a letter combination. This Code provides further information, among others the printing process and the paper of the selected library.
  • When the revision number changes, or when spot colors have been updated in the cloud, the Status of the affected libraries will change in the PantoneLIVE dialog from up to date to needs update. In this case, click on Update and the libraries will be updated in ZePrA.
  • Standard libraries can be edited in ZePrA, which means that spot colors can be copied, modified, deleted, or exported from one library to another, and Lab values can be edited. This is not the intention of PantoneLIVE libraries and are prevented by ZePrA.
  • The Lab values of PantoneLIVE spot colors are displayed as rounded numbers in ZePrA; however, internally ZePrA calculates the spectral measurement values with full accuracy.
  • To aid recognition of PantoneLIVE libraries, these libraries are marked with a PL: in the drop-down menus of the sub-dialogs under Configuration and in the Spot Color Report.
PantoneLIVE licenses in ZePrA

ZePrA allows direct access to PantoneLIVE®. A ZePrA spot color module license and an active PantoneLIVE® Production license from X-Rite are required. PantoneLIVE® libraries will then be available for use in ZePrA.

PantoneLIVE licenses are computer-bound and may even be application bound. If the computer (and ZePrA) is not enabled, you will receive the following error message in ZePrA (see screenshot):

To activate a PantoneLIVE license, open the page My PantoneLIVE of your My X-Rite account. The list with available licenses is found at the bottom of the page. If an Unused license is present, click Edit. This opens the dialog for this license, and you have two options to activate it:

  1. Activate the license by selecting Use this activation yourself and click on Done. In ZePrA, you can close the error message with Cancel and login again. Since the activation has already been done on the My X-Rite website, entering the activation code is not required.
  2. Do not change anything on the My PantoneLIVE website, simply copy the Activation Code and paste it into the error message in ZePrA. Then close the dialog box with OK. In this case, ZePrA completes the activation. The activation may be visible only after re-logining in on the My PantoneLIVE page.

Please check this YouTube video for the licensing procedure.

In case of problems with licensing please contact the X-Rite support.

ZePrA | Spot Color Iteration

Spot Color Iteration

Iterate spot colors to improve or maintain quality

Iterate Spot Colors

Spot Color Iteration is a process that involves printing of the spot colors converted from ZePrA on the printer to be used for the print job, followed by measuring test charts and optimizing the color differences (expressed in deltaE2000) until the measured deltaE values are within the desired tolerances. Printing the test chart and applying the Iterate Spot Colors feature once only already results in an improved spot color rendering which is usually close to the optimum of this printer.

Why can spot color iteration be required?

First of all, be assured that ZePrA already calculates the best possible spot color conversion based on the target profile set under Configuration/Target Color Space. However, printers, inks and papers drift over time so that there are always some deviations from the state the printer was profiled. During spot color iteration we measure how converted spot colors are actually printed in the current state, and subsequently optimize the deltaE2000 values. The iteration report shows which colors are improved and where restrictions based on the color gamut or the spot color Calculation Method occur so they can’t be optimized further or if additional iteration steps are recommendable.

Procedure

Open the Iterate Spot Colors dialog right from the Spot Colors tab of the Configuration you would like to optimize or the Tools menu and follow the steps from top to bottom. A Spot Color module license is required to use the tool.

Step 1: First, select the Configuration you would like to use for printing. The option Convert Spot Colors must be enabled in this configuration.

Notes: The best approach for the iteration of spot colors is to set the Calculation Method to Precise Match or Visual Match in the appropriate Configuration.

The setting Use the least Amount of Channels may be insufficient for iterating spot colors. Importantly, spot color iteration will not work when the spot color conversion is set to Convert using Alternate Color Space from PDF.

Step 2: Select the source of the spot colors you would like to optimize. You can either choose a PDF or an image file with spot colors or a complete spot color library. In the following example we will use a PDF file with spot colors as source file.

Step 3: A test chart file will be created from either a PDF or Image File or a spot color Library. If you select a PDF file and click on the Save button, ZePrA will extract all spot colors (full tones) used in the file and convert them using the selected configuration. In this step select an Instrument Setting for your measuring instrument. In the Save dialog, choose either a PDF or TIFF file type to create a test chart which contains the spot colors as a strip optimized for your measuring instrument. In addition, the  associated reference file for measuring will be created. The newly created test chart needs to be printed on the printer to be used for the print job.

Note: The test chart contains the converted spot colors as given in the Configuration using the conversion settings and Calculation Method defined in the tab Spot Colors.

Step 4: Print the test chart on your printer. Do not apply any color management when printing the test chart.

Step 5: Subsequently, measure the printed test chart using ColorAnt/Measure Tool or an appropriate software. The required reference file which is needed for measuring the spot colors will be shown in step 3. Click on Measure to open the Measure Tool in ColorAnt. The reference file will be selected automatically so that you can use the tool right away for measurements with your instrument. For information on how to use the Measure Tool in combination with your instrument follow the instruction given in the online help. Alternatively you may use the provided reference file for measurements with other tools.

Step 6: This step is optional but highly recommended. If you click on Save Report a Spot Color Iteration Report will be generated. The report provides you with information about the achieved and measured deltaE values.

The last column of the report – Status – provides status information such as improvements, recommendations about further processing or warnings. If the deltaE00 value is already very low (lower than 1) further optimization is not needed and the color is marked green. Colors that are marked yellow are higher than 1 but below 2 dE00 and colors marked orange are higher than 2 dE00. For colors that have been improved by an iteration the improved value is shown in brackets expressed as deltaE behind the status. If a spot color is out of gamut or optimization is not possible due to restraints from the selected configuration those colors are marked accordingly. A Legend below the table of the report explains the different statuses.  If a color is marked as Optimizable, the value in brackets behind the status indicates the maximum improvement to be expected.

Step 7: When clicking the Apply button the optimized spot colors (based on the measurement data) will be calculated and applied in the Configuration. Only tick the checkbox Iterate all Spot Colors if you would like to iterate all spot colors. We recommend to deactivate the checkbox in order to include only those spot colors in the iteration which can actually be improved. Consequently, if the checkbox is disabled, spot colors which are already marked as Good in the report will not be optimized further.

A feedback message informs the user when a spot color iteration has been applied successfully.

You will find the optimized device values (Output values) in the table of the tab Spot Colors under Configuration. They will be marked as Iterated in the column Information of the table. 

Expert tips: It is a good idea to Export the optimized spot color table of the tab Spot Colors. This will give you the chance to revert to these values in case you do some further iterations or change some values manually. Another tip in case you would like to revert to the original values without iteration is to use the Reset button in the Spot Color Iteration dialog. This deletes the iterated colors from the table.

Additional information

If you would like to evaluate the improvements in terms of deltaE2000 after Step 7 you need to print the optimized spot colors once more. To do so click on the Save button  in Step 3 of the Iterate Spot Colors dialog to create a new test chart file with the optimized device values and a new reference file. Make sure to use the second  testchart file when printing and measuring rather than the first one! After measuring and saving a new Report you can assess the improved deltaE00 values. You can continue to iterate by simply clicking the Apply button in Step 7. Or, in case the deltaEs are fine and further iteration is not recommended, simply close the dialog without applying the new measurements.

If the selected source file does contain spot colors which have not been considered in the selected configuration, an error message will appear as the test chart cannot be created. For that reason we recommend to convert the source file containing the spot colors integrating the wanted configuration prior to the iteration, or to verify them using the Spot Color Report in order to ensure correct settings in the configuration.

If you would like to optimize the creation of the test chart for you measuring device (for Step 3 of the iteration) you can create your own settings using the tool Export Chart in ColorAnt. The newly created settings are available in the drop-down menu Instrument Setting after the dialog Spot Color Iteration has been closed and reopened.

The measurement data that has been transmitted from Measure Tool to ZePrA in Step 5 is saved for later use in the shared folder for all users under ColorLogic/SpotColorMeasurements (Windows: C:\Users\Public\Documents\ColorLogic\SpotColorMeasurements. Mac: \Users\Shared\ColorLogic\SpotColorMeasurements).

ZePrA | Applying Correction DeviceLinks

Correction DeviceLinks

Modify target profiles with updated profiles or correction DeviceLinks

Apply Correction DeviceLink Profile

The more reliable the color behavior of your press and the more accurate the associated ICC profile for the printing process, the better the color conversion with ZePrA. In practice, however, things often look different. Fluctuations between paper batches, varying tonal value increases or fresh printing inks deviate from the ink series last used, which leads to color deviations and differences in the tonal value distribution.

To compensate for these fluctuations and deviations, CoPrA SP* with its Update Profile module is part of ZePrA’s SmartLink module. Instead of generating a completely new press profile and DeviceLink profile in case of deviations, a correction DeviceLink profile can be used to adapt to the changed conditions.
Very little information, such as the spectral measurement values of dot gain strips or, even better, of the Reprofiler measuring strip provided by CoPrA SP*, will ensure that your press produces the same color impression as before the deviation.

The Correction DeviceLink profile will be applied after the color conversion defined in your configuration. So you can continue to use your tested and proven DeviceLink profiles and do not have to replace them due to a change in the target color space of your press.

Note: *SP = Serialized Profiles. The profiles created with CoPrA SP are encoded with the serial no. of the ZePrA color server and can only be used there.

Update/correct the target profile in CoPrA

CoPrA’s Update Profile module allows existing ICC profiles to be updated with a few measurements. Correction DeviceLink profiles based on updated profiles can optionally be created for application on print data. These profiles can be selected in ZePrA under Configurations in the Document/Target tab by activating the Apply Correction DeviceLink Profile checkbox in the Target Color Space control panel. ZePrA versions prior to 4.6.2 do not support this profile type.

Procedure

  1. Select a measuring strip. CoPrA contains two Reprofiler measuring strips for different measuring devices for CMYK and RGB-based printing systems. For other color spaces, ColorAnt can be used to create suitable measuring strips.
    (1) The Reprofiler measuring strip small is available in a one-row and a two-row version. The one-row version can be placed more easily in the trim area of a printing press. The two-row strip is more suitable for digital printing or inkjet systems.
    (2) The Reprofiler measuring strip large contains considerably more color patches and is therefore better suited for optimizing larger color variations, as well as in digital and inkjet printing.
    Note:Besides the included ColorLogic measuring strips, other measuring strips can also be used, for example Ugra/Fogra Media Wedge, IDEAlliance Media Wedge, ECI GrayControl Strip, ECI bvdm TVI or UGRA UDKS Wedge. Alternatively, you can use an existing measurement file that reflects your current printing conditions.
  2. Print the measuring strip. To do this, deactivate the color management settings, i.e. no simulation of a printing condition will take place. This is especially true for digital printing systems.
  3. Measure the measuring strip with a spectrophotometer.
  4. The Update Profile tool in CoPrA optimizes the ICC profile of your target profile (= printer profile selected as Target Color Space in ZePrA).
    Note: If you use the Apply Correction DeviceLink Profile function, you do not need to replace the profile set as the target color space because this is done elsewhere – see below. 

Applying the correction DeviceLink profile in ZePrA

  1. In Configuration, Document/Target click the checkbox Apply Correction DeviceLink Profile. If there are no correction DeviceLink profiles, the option is grayed out.
  2. Click Settings to open the Correction DeviceLink Profile dialog and select a correction DeviceLink that has previously been created by CoPrA.
  3. The corresponding optimized target profile should also be embedded in the converted file (Embed updated Target Profile instead of the Target Profile). This will make this profile the new Output Intent of the converted PDF file. The updated target profile is shown below.
    Note: ZePrA checks whether suitable Correction DeviceLink profiles and optimized printer profiles exist for the selected Target Color Space. Only corrected or optimized profiles are shown and can be selected after activating the Apply Correction DeviceLink Profile checkbox. If there are no Correction DeviceLink profiles, the checkbox is grayed out.

ZePrA | Spot color processing

Spot Color Processing

The spot color module of ZePrA allows spot colors of PDF files to be converted accurately into CMYK, RGB or Multicolor color spaces. It requires a spot color license, which is included in ZePrA XXL, but can also be purchased as an Add-on module.

The spot color module

  • is part of ZePrA XXL, including a Multicolor license.
  • is available as an Add-on for ZePrA (requires a spot color license).
  • is part of the Multicolor Add-on (requires a Multicolor license).

Spot Color Libraries

Spot Color Libraries and spot colors can be clearly managed in ZePrA’s spot color module. It can be opened with a click on Spot Color Libraries in the sidebar.

Here libraries can be created, added, viewed and customized. Individual spot colors can be edited, imported or measured. For example, spot colors from color fans can be measured with a spectrophotometer or Lab values can be entered manually. Color tables with spot colors can also be imported. Supported formats are Named Color ICC profiles, Photoshop ACO color tables, Adobe ASE color tables (from InDesign or Illustrator), text files in CGATS format or CxF files, such as CxF/X-4. You can import your PantoneLIVE color fans stored in the cloud using the PantoneLIVE button.

Note: PantoneLIVE® from X-Rite is a cloud solution for digital storage of spectral spot colors. For using PantoneLIVE, licenses for the spot color module of ZePrA and for PantoneLIVE from X-Rite are required. Under My X-Rite you must unlock your licenses for use in ZePrA. For information on how to do this, see PantoneLIVE.

Both Lab and spectral color values are supported. Spectral measurement data are to be preferred, as they give the best results internally.

For more information about spot colors and spot color libraries, see:

Spot Colors

Edit Spot Color

PantoneLIVE

Converting spot colors to pixel-based formats: Spot colors from image files (ZePrA supports the pixel formats TIFF, PSD and PSB) can be converted by generating the spot colors as alpha channels with spot color attribute.

Without spot color module: The alternative replacement colors specified in the PDF file are used to convert spot colors to the target color space, resulting in reduced quality. For more information, see Working without the Spot Color Module.
Note: In many cases, standard conversion without the use of a custom spot color library will not result in a sufficiently good spot color reproduction or a good printing replacement process color.

Retain user-defined spot colors: Maintaining custom spot colors is critical to print production. For example, in packaging printing, this is necessary to preserve areas for die cut, braille, varnish, fold and crop marks.

Spot Color Processing – The Classic Method

Normally, spot colors (DeviceN colors without CMYK components) are resolved and converted into the target profile. The replacement color (Alternate Color Space or replacement color in the PDF) that is assigned to each spot color in the PDF is used. The PDF alternate color space for a spot color is usually specified in CMYK or Lab and is specified in the PDF-creating graphics or layout application (for example Adobe Illustrator, InDesign or QuarkXPress).

By using the appropriate settings, ZePrA performs a DeviceLink conversion from the replacement color to the target color space. Nevertheless, conversion with the replacement color value is a rather inaccurate solution, especially if the replacement color for the spot color is specified with device-dependent CMYK values. But even if the replacement color is defined by a measured Lab value, the ICC color conversion results in a color conversion that is mostly not sufficiently accurate and above all not well printable.

Example: The spot color PANTONE 266 C of a PDF document has an alternate color value of CMYK = 70/81/0/0. Printed in high-quality offset printing on coated paper according to ISO Coated V2, these CMYK process color values would produce a dark violet color that is 32.7 DeltaE-76 or 9.8 DeltaE-2000 away from the actual spot color (see screenshot). The color lies outside the printable color gamut and is therefore not printable in four-color offset printing.

The same spot color with the same PDF replacement color value would also only be reproduced with a large color error of approx. 9 DeltaE-2000 in a Multicolor printing system with 7 colors, which could simulate the spot color very well. In our example, a conversion via a stored CMYK replacement color value will therefore lead to an extremely unsatisfactory color reproduction in both printing processes.

Working with spot colors

An exact conversion of spot colors requires color libraries with correctly measured spectral color values on the one hand, and additional DeltaE minimization on the other. With a DeltaE minimization, our example colour PANTONE 266 C in the Multicolor 7C printing process could even be reproduced exactly without color errors (see screenshot).

Often several Spot Color Libraries are created for identical spot colors because it is necessary to use separate and optimized color values for different substrates or printing processes.

Spot Color Libraries can use measured gradations of spot colors, so that gradations of the spot color can be reproduced optimally (for example, the 50% value of a spot color).

In order to better calculate overprint simulations, the measured values can be stored spectrally (also spectrally on black color). Then the calculation is done with an intelligent spectral color mixing model.

ZePrA is able to maintain overprinting properties if this is possible.

For elements consisting of a mixture of spot colors and other process colors, the color appearance is simulated in the best possible way after the spot color has been resolved.

When converting to the target color space, as few process colors as possible can be used while still maintaining the smallest possible visual color difference. In our example, the optimal solution is to use only the violet process color (see screenshot) and still achieve a color error of only 1.0 DeltaE-2000.

Spot colors can be converted to a desired target value (for example, a process color) regardless of the smallest possible DeltaE. This is necessary for texts or barcodes, among other things.

Spot colors can be excluded from a conversion, for example when spot colors are used as crop marks, gloss varnishes or braille characters.

ZePrA | Working with Transparencies

Working with Transparencies

Working with Transparencies

Transparency Flattening and Sharpening

Many users often think of only photographic images when sharpening PDF data.  However, when flattening transparencies, vectors and texts can also be converted into pixel-based images. These pixel-based images are treated like photos when the Sharpening option is activated This can lead to adverse results. A difference in sharpness between adjacent objects in the form of a vector or text can cause visual issues and inconsistencies. For production, sharpening effects should always be tested in advance.

Use caution when flattening transparencies with ZePrA. Sharpening takes place before conversion and flattening. In contrast, sharpening without transparency reduction in ZePrA takes place after conversion.

Depending on the composition of the elements in the layout software on the one hand, and the parameters for flattening the transparencies and sharpening in ZePrA on the other, extreme sharpening can produce visually undesirable effects.

The negative effects only become apparent at the most extreme sharpening Amount with a Threshold of 0. Since JPEG artifacts usually show minimal color differences, a high Threshold is the most important factor to avoid unwanted effects.

The following example shows the effects of different sharpening levels. In this case, the graphic designer has placed an object with drop shadow over a gradient.

When flattening the transparencies, the flattened elements were compressed using the JPEG format. With an extreme sharpening setting, the artifacts part of the gradient underneath the drop shadow, which is usually invisible, become intensified when converted into a JPEG image. The following sharpness settings were used from top to bottom:

  • No Sharpening
  • Radius 0.35 points, Amount 80, Threshold 8
  • Radius 0.35 points, Amount 300, Threshold 4
  • Radius 0.35 points, Amount 500, Threshold 0

 

Converting PDF files containing transparencies

When converting PDF files with transparencies, the transparencies can either be preserved or flattened using Transparency Flattening.

During conversion, each object – with or without transparency – is converted separately, preserving the structure of the PDF document.

Unfortunately, there are so many variations in the blending of transparencies and the stacking order of semi transparent objects that there is no simple rule as to when transparencies ought to be flattened or not.

Flattening requires the resolution of the platesetter to be specified; therefore, it is best to perform transparency reduction as late as possible in the workflow.

ColorLogic recommends performing the conversion in ZePrA first without transparency flattening and then to check the converted file with a transparency-compatible PDF viewer (e.g. Adobe Acrobat Pro or Callas PDF Toolbox). If the converted file is visually correct and the desired total amount of coverage is maintained, continue working with the file.

If the file contains artifacts after conversion, uncheck the Convert all transparent Elements in PDF Files checkbox under Configurations/PDF and convert the file again.

This changing this setting often helps to preserve the impression of the original file (see figure below), since ZePrA excludes certain transparency modes from the conversion.

The checkbox Convert all transparent Elements in PDF Files is active by default.

However, if there are still artifacts after deactivating this function, use Transparency Flattening.

Note: Transparency Flattening is based on the Callas SDK, which in turn uses Adobe’s PDF engine for transparency flattening. Therefore, the results achieved with ZePrA’s Transparency Flattening are identical to those achieved with the current versions of Callas pdfToolbox.

Converting Spot Colors containing Transparencies

For transparency flattening of PDF files containing transparent objects composed of process and spot colors, Adobe’s transparency flattening preserves spot colors to preserve the impression of the original but sets them to “Overprint”. Transparency-reduced PDF files should therefore always be viewed with “Overprint preview” enabled in the PDF viewer (e.g. Adobe Acrobat Pro). Simple PDF viewers, such as the Preview in macOS, or many apps on tablets, display such files incorrectly due to the missing overprint feature.

If ZePrA is to be used for high-quality spot color conversions instead of the PDF preflight program or the RIP, activate the checkbox Convert Spot Colors under Configurations/Spot Colors and spot colors are converted to process colors in the best possible way.

Note: Spot colors that are converted will be set to “Overprint” due to the transparency reduction and can mix with process colors. This can lead to unwanted results and the disappearance of converted spot color objects. If this happens, select Transparency Flattening and either Dissolve Overprinting or use the extreme method Rasterize Document.

Transparency Flattening, Image Quality, and File Size

When reducing transparencies, the resulting rasterized objects are created with lossless ZIP compression. This guarantees the best quality but also results in larger files compared to JPEG compression. Even PDF files with JPEG-compressed images will have ZIP-compressed images due to transparency flattening. If the file size is to be reduced, and a reduced quality is acceptable, change the Compression Method to JPEG (in the Image Quality panel under Configurations/Options).

Note: The Compression Method is only considered by ZePrA when performing a conversion. When performing a Transparency Flattening without conversion, no compression change is made, and rasterized objects are ZIP-compressed.

ZePrA | Sharpening

Sharpening

(For example, in-house RGB workflows)

Sharpening Images

Optimal sharpening refers to the scaled final format of an image in the print data. The following section assumes that editing high-resolution RGB images, placing these images in the layout program, creating the PDF data, and processing the data with ZePrA are connected workflows within an application suite. The summary of these steps is referred to here as an in-house RGB workflow.

With in-house RGB workflows it is possible to work with high-resolution originals of the RGB images in the layout program and then generate a PDF/X-3 or PDF/X-4 file that also contains high-resolution RGB images. Finally, ZePrA handles the color management, the downsampling to the final resolution, and the sharpening. 

After the RGB images have been reduced to the final resolution and color converted to CMYK, a stronger sharpening than is usual for pre-sharpened CMYK images should be applied in ZePrA. To do so, select Strong Sharpening of RGB and Gray Images in ZePrA under Configurations/Options/Sharpening/Preset.

For documents that contain RGB images and already sharpened CMYK images it is recommended to limit sharpening in ZePrA to RGB images.

Note: If transparencies are used in the layout program, it is essential to ensure that there is no  transparency reduction, as RGB data is inevitably converted to CMYK if the RGB image is affected by transparent objects. Transparency reduction is mandatory when creating PDF/X-3 files, whereas transparency is explicitly allowed in PDF/X-4 files. If all RGB images are sharpened in ZePrA, the transparency reduction, should also take place in ZePrA.