Total ink limit for CMYK plus white on WT7900 printers

In the Precision Color Media Configuration wizard, the Total Ink Limit step determines the maximum amount of ink to use for the media.

The printed sheet includes several total ink limit charts. Each total ink limit chart is printed with a different total ink limit (TIL). Each chart includes a group of color patches and several solid rows of color printed on top of a white vignette.

The white ink behind the color patches represents the selected white level for the media configuration. Evaluate the color patches from the front and back of the media. Identify the color patches with the best gamut and the white patch with the least noticeable halo. The halo is most visible from the white side of the proof.

For the solid rows of color, evaluate the charts from the front and back of the media. Evaluate opacity and color gamut. Note that lower opacity levels allow larger color gamut and vice versa. Identify the TIL value that is the best compromise of both color gamut and white opacity or covering power. Covering power is the ability of the white ink to hide the colors printed underneath. If you will use the media configuration at only the selected white level, concentrate your evaluation on the area of the row that is printed on the white level that you selected for the media configuration.

When you evaluate the charts, consider these characteristics:

• Saturation—Consider how much ink is used to print each chart. Higher saturation increases gamut, but decreases the hiding power of white ink. Lower saturation decreases gamut, but increases the hiding power of white ink. Too much or too little ink tends to produce artifacts.
• Artifacts—Consider where artifacts appear in the charts. If the artifacts appear in the area of the white vignette that you won't use, the artifacts may be irrelevant for you at the identified total ink limit.
• Covering power of white ink—Consider how the level of white ink affects the CMYK colors. For example, you may want a level of white that allows very little of the other colors to show through or vice versa.

The total ink limit is often a compromise between the most saturation possible with the fewest artifacts and the needed covering power of the white ink.