Understanding Linearization

In Knowledge Base, Print Quality Analysis by Mary Schilling0 Comments

Inkjet Drops controlled and uncontrolled

The key to print quality and color management is controlling the migration of the ink into the paper. The size of the drops jetted along with the pattern which forms upon contact with the paper surface can make any print go from crisp and clear to dark and plugged up. Linearizing your device before the ICC color profiling step is critical to controlling how dots spread, bridge and merge into each other.

Oftentimes, people use the terms linearization and profiling together in a way that is confusing. They are two different steps. Linearization is an iterative process used to control dot spread for each color for a particular device, ink and paper GSM using software and press settings. It is time consuming but necessary due to the nature of inkjet devices.

Aqueous inkjet ink uses water as the colorant carrier. Paper by nature is incredibly absorbent. Specific chemistry is added to inkjet grade papers at the fiber mixture level or applied after the paper is formed. This chemistry allows a level of porosity that promotes water absorption while minimizing the absorption of the ink colorant. A jetted drop will spread differently depending on the paper type and chemistry, as well as, the printer speed and drying settings. This is why conducting the custom linearization process for each paper is critical to color and clarity.

Some high speed inkjet presses have an in-line linearization option which can be added to the machine. If you have this option, always use it during your paper setup. This linearization process should be conducted for each different paper grade and weight and saved with the paper profile (not the same as the color profile) at the press level and used each time that particular paper grade and weight is loaded on the printer. Only then can ICC patches be printed and scanned to create a color profile.

If you don’t have the linearization option on your inkjet device, you should buy a color profiling package which allows the linearization step to be included in the creation of the final ICC profile process. Packages will include various process color ramps or G7 patch patterns to use for the linearization step. Regardless of the pattern, your dot spread must be controlled before accurate colors can be achieved by the press.

Now, lets clarify ICC Profiles. Often the role of ICC profiles are overstated and inaccurately referred to by some as “color correction.” An ICC profile is simply a look up table of color values achievable by the printer with specific paper and press settings. Think of an ICC profile as a map which gives an Adobe design file consisting of RGB, CMYK and Lab color values directions to the nearest CMYK reproducible value for that color. An ICC is only the “traffic cop” managing the color direction, not correcting it. A profile will not minimize dot spread if the paper causes the ink to spread inconsistently.

As you can see linearizing your substrate regardless of the paper type is important to print clarity and should always be included in your high speed inkjet color management process before any ICC creation.

 

Was this post helpful?

Help us out by registering (free) and provide some basic information that will help us make Inkjet Insight content more relevant. You can also give us feedback directly on a post you like, a post you don’t like or something else on your wish list. We’re listening and learning.

Share

Discussion