Color Channels
Image with spot color channels in the Manual Job Manager.
The color channels from the input image are listed in the Channel column (1) in the order of printing from top to bottom.
You can change the order by selecting a color channel and clicking the arrow buttons on the left side to move the channel up or down in the list (2). Note that CMYK is always printed as one set sequence, which means that you cannot move or swap these channels. On the screenshot you can see a print sequence, where a white spot color will be overprinted by process channels.
The mapping of channels to spot colors from a spot color database is shown in the Color column (3). You can manually remap channels by picking a spot color from the selected spot color set or by defining a custom spot color. You can also define rules for an automatic mapping of image channels (Channels button on toolbar, 4).
For multicolor proofing with GMG OpenColor, the channel and print order can be defined either by the selected OpenColor Proof Standard, or dynamically, according to the current requirements (Channels > Print Order). Supporting the MatchMyColor color plugin system for Adobe Illustrator, GMG ColorProof is able to read the XMP metadata of the input file, automatically assign the correct measurements, and create a matching profile on-the-fly.
Channels table
| Column | Description | See also |
|---|---|---|
| Channel |
Channel name from the input image. An RGB image contains the channels Red, Green, Blue. A CMYK image contains the channels Cyan, Magenta, Yellow, Black. A multicolor image file has at least one spot color channel (any channel name). It can have any number of spot color channels, plus Cyan, Magenta, Yellow, Black. Multicolor RGB + spot color images are not supported. CMYK and multicolor images only: You can deselect any input channel by removing the check mark in the first column of a channel row. Deselected channels are not shown in the preview and are not printed. |
|
| Cali. | Indicates whether a spot color uses an MX3 printer calibration or not (defined in the spot color set). Standard process colors (CMYK, RGB) always use the printer calibration. (The check mark icon shows only that an MX3 is used for processing the channel, but the printer calibration is not validated. For example, you could use a linear MX3 if you do not want to use an MX3 for a process color.) | |
| Invert | If activated, the color of the channel is inverted. The brightness value of each pixel in the channels is converted to the inverse value. For example, a pixel in a positive image with a value of 255 is changed to 0, and a pixel with a value of 5 is changed to 250. | |
| Color |
The color currently mapped to the original channel of the input image. You can change color mappings by clicking in the Color cell and choosing a desired color from the drop-down list. Custom: Instead of using any predefined colors, you can also define a custom color value (Tonal Value in percent). If a PDF/PS file contains cut paths, these can also be defined by selecting Define Cutting from the drop-down list. |
|
| Gradation | You can assign a gradation correction (sfg) file created in GMG SpotColor Editor to a spot color channel. | Printing Spot Colors with a Gradation Correction |