If you solely want to apply gradation curves to data that are otherwise ready for the press, you can use Version 2.3 to create corresponding configurations with the Automatic Setup Wizard. Gradation curves are then applied to process colors and/or spot color channels, but the document color space remains unchanged. So, it is best to apply pure gradation corrections to press-ready PDF/X-1a files, which consist only of CMYK and possibly spot colors.
The Automatic Setup Wizard now has a fifth workflow option: Apply gradation curves only. You have three possibilities for creating a pure gradation workflow:
- Use curves from external file: Load an external file with the gradation curves for process colors and/or spot colors. ZePrA reads the gradation curves from the loaded file, and automatically assigns them to the corresponding process colors. If the external gradation curves file also includes spot-color curves for defined spot-color channels, ZePrA creates the corresponding spot-color channels in the configuration, and assigns the corresponding curve to each color.
- Start with linear external file: If an external file with gradation curves does not yet exist, but will be generated in the production process, you can create a corresponding configuration with initially linear curves beforehand. In this case, ZePrA automatically creates a file containing linear gradation curves in the base folder of the queue. In the production process, these curves are then simply overwritten with an updated file containing new curve information that is immediately applied to files in the workflow.
Note: ZePrA detects any changes in the external gradation curves file, i.e. any updating of the curves in the file, in both Workflow 1 and Workflow 2. ZePrA instantly adopts the gradation curves, and applies them to the files awaiting conversion in the queue, without requiring a restart. The prerequisite is that the gradation curves file of the respective configuration is overwritten with the same name at the corresponding storage location.
- Select Curves: If you do not work with suitable tools that create the external file with gradation curves needed for workflows 1 and 2, you can create a configuration using the static gradation curves supplied with ZePrA, or using curves you have created yourself by means of the Curve Management function (in the form of a DeviceLink-ICC profile). Simply select the required gradations from the choosers for the process colors Cyan, Magenta, Yellow, and Black. Needless to say, you can change the curves in the configuration at any time.
In the next step of the Automatic Setup Wizard, you have the choice of normalizing the data, or of deactivating the Normalize checkbox in order not to perform normalization. When working with PDF/X-3 or X-4 files, which may possibly contain RGB objects or CMYK objects with embedded profiles, you should have the file normalized by ZePrA. ZePrA subsequently applies the curves to the normalized file. Select a Document Color Space to be assumed if there is no Output Intent in a PDF file. In addition, always activate the Prefer Output Intent checkbox, so that an existing Output Intent always has priority over the set Document Color Space and is preserved.