Ink Limiting is the process of restricting the total amount of ink applied to a media by adjusting the maximum percentage of the color values in a processed image.

The purpose of ink limits is to prevent over-saturation of three and four color combinations. As far as determining where to set the Ink Limits, generally one should look for the following indicators:

1. Point at which Bleed, Mottling, Embossed, or Raised look occur in the patches.
2. Point at which Hazing (gloss media), Sheen (Matte media) occurs.
3. Point at which a darker hue not being achieved (i.e., ink is simply being wasted).
4. Good two color combinations vs. all of the above.

Notes: The ONYX Profiling Lab does not use (or recommend using) the Basic Ink Limit settings.CMYKOG and CMYKRGB printers each have unique ink limit swatches with additional rules for setting Advanced Ink Limits. Black Ink is not limited and therefore compensation for actual black ink present needs to be made. See Profiling For CMYKRGB.

Print The Swatch

The first step is to print the swatch.  No device is needed for this step.  You will be evaluating the swatch based on visual observations.  Please be aware that for some ink configurations such as CMYKRGB, etc you will be printing a very large swatch.  On some Grand Format printers with wide media it is suggested that the file be opened into Preflight and enlarged 50% - 100%.  This will make it possible to have a more Real World evaluation.

Interpreting Ink Limits 

Basic Ink Limit

Review the swatches and if you can choose a value that is acceptable across all rows, you may use Basic Ink Limits. Click > Read Swatch and enter in the value as seen on the column of your choice.

If specific rows require different settings depending on the combinations, you must enter in the values on the Advanced Ink Limits tab.

Advanced Ink Limits

The numbers located on the left-hand side of the printed swatches correspond the the fields within the software.  When evaluating the Ink Limit swatch, review each row or group of rows and keep the following in mind:

1.   Set the ink limit as low as needed for each "group".  That means for group 1 Cyan, set the ink limit to the point where there is no bleeding, puddling, etc.  Do the same for each "group"  It is acceptable to set ink limits as low as 2.2 in order to control the unacceptable output issues.

2.   Set the ink limit for Hi-Fi Colors (CMYKOG, etc.) based on the lowest ink limit for the group.  These printers will have large "groups" with various combinations of the various colors.  The ink limit for each group must be set low enough to eliminate the undesirable artifacts.

Note:  If you are profiling CMYKRGB you will have a different swatch that contains additional rows of ink combinations needed for the profiling workflow. See Profiling For CMYKRGB.

Black Ink Compensation

As ink limits are lowered there may be some apparent "lightening" in 3 color pixels.  The second row in groups 4, 5, and 6 in the Ink Limit Swatch are useful to see if this is occurring.  This apparent lightening is caused as Reds, Greens, Blues, etc. are created with less ink.  In order to compensate so that the darker 3 color pixels have the correct color appearance you may need to increase the level of "Black Ink Compensation", also known as BIC.

 
 
For example if you set your first round of ink limits and then do a test print and see that your colors are turning "gray" before the are turning "black", you will want to use Black Ink Compensation. This increases the use of black ink to maintain dark saturated colors.

One way to determine whether the BIC selection is valid is to print another Ink Limit swatch after setting the ink limits (prior to making a BIC setting). When reviewing this print you will want to look for a point from about 2.3 to 3.0 where the hue suddenly stops getting darker and actually gets lighter before getting darker above 3.0. Its been found that Red and Green (4/5) are typically the easiest areas to observe this. After setting a BIC, you can print the swatch again to see if this lightening of the hue was corrected. Make adjustments as needed.

The following examples are typical of the settings we use in the Profiling Lab based upon the average Ink Limits (1-7):

• 1.5 - 2.0 → BIC = 4-5
• 2.0 - 2.5 → BIC = 3-4
• 2.5 - 3.0 → BIC = 2-3
• 3.0 - 4.0 → BIC = 1-2

To determine the needed BIC amount:

1. Set the value (range 1 - 5)
2. Check the box to Reprint Swatch
3. Click > OK to reprint the swatch
4. Evaluate the new swatch to determine if the Black Ink Compensation should be reduced or increased

Once you have determined Ink Limits you are now ready for the next step - Generating an ICC Profile.

Back to Media Model.

Back to Profiling Step By Step.

BIC.jpg (image/jpeg)
InkLimitSwatch.jpg (image/jpeg)
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AdvancedInkLimits.jpg (image/jpeg)
AdvacnedInkLimits.jpg (image/jpeg)