There are 4 ways to manage color in the Navigator DFE.
- ICC color transformation
- Spot (pantone) Color Adjustment tool
- Global Color Adjustment tool
1. Calibration is covered in a separate chapter. Editorial note: For many users calibration is the most important step. Our calibration process is designed to align your printer with the reference printer that made the ICC profiles. Once your printer has been calibrated, it will print like the reference printer. Because of this, the built-in ICC profiles will give you color accuracy. After calibration, you may skip to using the methods detailed as #3 and #4; the color adjustment tools. ICC Profiling has been done for you by your printer manufacturer or supplier. Just using one of our shipping Paper Profiles in conjunction with your calibration will do the trick.
However. Getting a calibration and a color management configuration married in the system is a topic we will cover right here.
If there is a calibration with the exact same name as the color configuration, then the system will use that. So, if you make a color configuration named "MyPaperProfile1" and you want to use a specific calibration with that, it should be named "MyPaperProfile1" as well.
If there is no matching calibration then the system will use whatever is selected as the default calibration in the Render Config inside Navigator Configurations Editor.
Example case: you want to simply use "Linear" as your calibration and work from there. Set "Linear" as the calibration inside Render Configs. Then, use whatever color configuration you want. The system will first check if there is a calibration with the exact same name as your color configuration. If it does not find one, it will use the one selected in your Render Config.
2. ICC color transformation
The system ships with a variety of ICC profiles for you to use. To configure your ICC color management settings go to the Settings button from the main screen. From there, choose Configuration Editor. The Color Profiles section will look something like this:
You will need to select a Paper profile. A "Paper profile" is a collection of settings and ICC profiles, working together to calculate the color transformation the color engine will apply to your job.
In Harlequin terms, a Paper Profile is a "ColorPro" setup.
A Paper Profile requires a CMYK input profile, an RGB input profile, an output profile, and a rendering intent,
Other settings are optional.
Input profiles for CMYK and RGB are pre‐installed. Output profiles are also supplied. Should you need more, please contact your sales or support representative.
Input CMYK profile. An input profile colorimetrically transforms color data from a device‐dependent color space to a device‐independent color space, where the color management engine can process the data and supply it to an output profile, which you can choose separately to suit your output device.
Input RGB profile. The RGB input profile translates the input to a device‐independent color space so that the resulting colors match the colors that can be produced on a monitor. RGB data is converted to the color space of the output profile.
Device (or output) profile. This profile does the opposite of what an input profile does. Based on information about the output device and imaging conditions, the output profile transforms the device‐independent color space back into a device‐dependent color space. The Output profile is the ICC profile of your printer, ink, and paper.
Any color the device can reproduce (with the intended setup and viewing conditions) is reproduced exactly. Colors outside the device gamut are mapped onto a “nearby” point in the gamut. There are various ways in which a color might be out of gamut. For example, it could be too saturated, lighter than the paper color, or darker than the darkest imageable patch. Colorimetric reproduction is appropriate where an exact color match is required. For example, you may choose a colorimetric strategy when you are reproducing a logo in corporate colors.
This style aims to reproduce colors exactly, except that the luminance (how light or dark a color is) is scaled so that the darkest possible color is mapped to the darkest imageable color, and the lightest possible color to the paper white. This style may change the hue (degree of redness, blueness, and so on) of any color, and is almost certain to affect the luminance of most colors. Some scanners and applications produce data that has been adjusted so that the lightest and darkest point are encoded as maximum and minimum lightness. For interpreting this kind of image, the relative colorimetric style is appropriate.
This style maps the entire device‐independent color space onto the gamut of the printer by compressing the range of in‐gamut colors to make room for out‐of‐gamut colors. It is appropriate for rendering photographs and similar reproductions of natural scenes.
This style specifies that the saturation of the colors in the image is preserved, perhaps at the expense of accuracy in hue and lightness.
Editorial Note: If you don't know what to do and you're looking for a recommendation then use Relative Colorimetric. Relative colorimetric is often the best choice for a professional printer.
An explanation of the options.
Color manage gray as CMYK
This style specifies that the saturation of the colors in the image is preserved, perhaps at the expense of accuracy in hue and lightness.
Treat spot colors as CMYK
Checking this option makes any spot color in the job use the input profile specified in the CMYK data field. When this checkbox is enabled, spot colors will always be treated as CMYK. If this option is not selected, the Pantone color is chosen using the XYZ Pantone lookup table (within the RIP), which in turn gives the proof a best match for the Pantone color but is not a good proof of what the color would look like on an offset press.
Editorial note: Don't check this box. If you are trying to simulate how Pantone colors print on a different CMYK printer, this may be a good choice. But if you're trying to use the latest technology and the latest Pantone libraries to get the best possible spot color match, then you need to leave it unchecked. It's a special purpose override.
Preserve 100% Process Black
Select this check box if you do not want the black‐only part of your input to be converted to a CMYK‐equivalent color by the color management process. This option is particularly relevant for black text because it avoids colored fringes.
Because this is such an important consideration we provide a control for this in the job ticket. Each time you submit a job you can choose to check, or not check, this box:
More editorializing: Leave it checked in all your color setups as a default. It produces black text with no undercolors that could possibly bleed out or misregister and look fuzzy! You can turn it off anytime you want to at the time of job submission. Unchecking it does make 100% black as dark as possible because the color management engine puts other inks into it.
Override overprint mode in job
There is a new PostScript operator called setoverprintmode which is the PostScript equivalent of the PDF gstate OPM flag. If an object is set to overprint and OPM or setoverprintmode is on, the RIP drops any colorants which have a zero value. This is called “implicit overprinting”. This is what the Override overprint mode in job option controls. If the Override overprint mode in job option is selected any overprintmode and OPM parameter in the job is ignored. If it is not selected, any overprintmode and OPM parameter in the job is used.
Overprint 100% Black
When this option is selected, the RIP overprints 100% black rather then generating knockouts in the other separations. The black channel or separation is generated as normal but, depending upon the characteristics of the other inks, may need to be applied last in the combination process so that it overprints all colors necessary. If this option is selected, overprinting occurs regardless of whether overprinting is switched on for that graphics object. There is no performance penalty incurred by using this feature—in fact, it may be slightly faster to overprint, given that knockouts do not have to be calculated. This feature only applies to black objects, not to individual pixels of a continuous tone image that happen to be 100% black.
Applying Overprint preview gives better quality results with blended colors.
The Overprint preview option overcomes problems with color managing blended colors. In this context, blended colors means both the compositing of transparency in PDF jobs, and also the overprinting of opaque objects in PostScript language and PDF files. In order to color manage blending correctly, the blending must be performed in the same color space that the designer worked in when creating the job.
When the Overprint preview option is off, the Harlequin RIP will perform color management of colors in the job before overprints. The RIP performs blending by using the available information to make a “best guess” at the blended colors, but at a late stage in the RIP process and without full knowledge of the color values and other graphics state attributes. This method usually makes the blended regions visible, although they are not correctly color managed. And if spot colorants are converted to process colors, overprinting of these objects is disabled by default. When the Overprint preview option is selected, color managed blending is performed in a single pass of RIP processing with its obvious efficiency benefits.
Use Black point compensation
Black point compensation is used when converting images from the color space of one device to the color space of another device. It accounts for the differences in the darkest level of black which can be printed on those devices. The implementation in the RIP will only work with color transforms composed entirely of ICC profiles, that is, the method will have no effect on device independent color spaces such as CalGray, CalRGB, CIEBasedxxx, but will work for ICCBased and embedded ICC profiles.
Convert RGB Black to true black
Some applications, and especially Microsoft® Word, use RGB colors for everything, including solid black—coded as 0 0 0 setrgbcolor (or 0 0 0 in a DeviceRGB color space). You should choose this option to force the RIP to intercept blacks coded in this way and convert them to (0 0 0 1) in a CMYK color space.
How to apply a Paper Profile to a print job.
When you submit the job, choose it from the drop down menu.
3. Spot Color Adjustment
The Navigator DFE contains licensed Pantone libraries so you get the best possible color match on your digital printer. To use those libraries you need two things:
- Input PDF files with defined spot color channels
- A Paper profile configured with the "treat spot colors as CMYK" turned OFF.
What if you want to get a closer match on a new paper?
Or what if you need to match a previous printed process instead of being "accurate"?
The spot color adjustment tool walks you through the process of printing patches to override those libraries and/or update them to contain new definitions. These new spot color recipes can be saved into separate color databases which may be automatically applied to selected jobs when appropriate. You may have as many spot color adjustment databases as desired.
(If you want to just watch the movie, skip down to the end of this section or go here)
This job has two spot colors. The spot color workflow might go something like this:
Bring the job in for the first time.
Click Test Print. (you will get 1 copy of page 1 printed out so you can check for color and positioning.
Should you decide that the spot colors need adjustment, edit the job and click the blue button to the right of the Spot Colors database dropdown menu. If you are in printing you'll recognize that as a representation of a Pantone fan deck:
We chose Pantone 121 for our adjustment. Notice the CMYK sliders. If you believed strongly in yourself you might just slide those to change the color. However, for more help selecting the new color recipe, click on the icon of the printer. That will give you a lot more help.
The swatch sheet page:
We suggest the most appropriate changes automatically, but there are some optional moves you could make concerning color choice, the degree of color change, paper size:
When you are happy with your swatch variety, print it.
Compare the swatches to printed material, or read them with a spectrophotometer.
If you choose to print them envelope size they will print on two envelopes.
The middle row prints on both envelopes. Overlap them and make your choices.
If you choose to print A4 or Letter you'll get this:
Here's how it works:
Whichever swatch you pick, you click.
Go to the interface and point at the one you liked on the prints. That will become the new center. In the example case, I'm picking the bottom center.
If you decide it's almost, but not quite, right, then adjust the color steps lower, and go again:
Once you are satisfied, click the check box. You'll come back to the color list and sliders. The original color has the arrow on it. The altered color is in the middle bar.
If you decide to undo your work you can reset to the original color by clicking the original color with the arrow on it. Clicking that button is to say "put the original color back in there".
Click and this becomes . . .this:
However, we are satified with our change and are keeping it!
If you wanted to keep it just for this one print then you would leave it to apply adjustments only to this job, as it is by default:
However, we are satified with our change and are keeping it forever!
If you want to be able to apply this change to jobs in the future you would save a spot color adjustment set. This is a database of spot color adjustments that can be automatically applied later.
Next time you run a job from this customer you can submit the job like the job ticket below and just hit "Print".
4. Global Color Adjustment
Global color adjustment is a simple curve adjustment on the mid-tones.
Unlike ICC profiling, or calibration, or spot color adjustment, global color adjustment is not scientific or targeted at particular elements in a job.
It's more of a 'quick and dirty' tool and it affects the whole job.
The interface consists of five sliders. One slider each for CMYK and one more for darkness/lightness. The darkness/lightness slider affects all 4 color channels together. You can stack changes. Examples follow.
How do you get a job darker?
Even darker but still color balanced?
How to make it lighter and yet more magenta?