Whatever happened to Hexachrome?

Answered by Stephen Beals, Digital Pre-Press manager and industry writer

Whatever happened to Hexachrome? A few years ago, there was some talk about 6 color hexachrome, now I don’t hear anything about it. Why didn’t this technology take off?

Hexachrome is alive and well, if not exactly flourishing. Hexachrome is a full color process that adds a fluorescent green and orange to the usual CMYK mix. This gives a standard offset printing press a much wider color gamut, particularly in the green and orange range of the color spectrum. The system for creating color separations for hexachrome production was developed by Pantone, a leader in the color specification business. Although it works well, and it is being used out there, there are several technical reasons the process has not caught on more than it has.

First, it is inherently more expensive for offset presses because two additional plates must be used. The fluorescent ink tends to be a bit more expensive too, but the biggest problem on press is that there are also six screens to contend with. To avoid screen patterns, hexachrome uses stochastic screening: a very high resolution and more random pattern of screening. Theta means the set ups that are standard for 4-color process have to be changed to print a six color process job. ALL of the colors need to change to make it work. Press operators vary as to how they respond to such changes. Most newer digital plate systems have no problem making the correct resolution hexachrome dot patterns, but it does take some experimenting and press profiling to get things set up initially.

Digital print devices, on the other hand, often are incapable of printing with hexachrome because they do not have the correct ink pigments or toner available. Of course some digital output devices CAN print hexachrome. It is of some interest that Hewlett Packard has developed a different 6-color process of their own opting for violet instead of green. They felt that the colors their customers wanted to hit were better served by those ink colors. The swatch books for the CMYKOV process were also created and licensed by Pantone. The process is available on HP's Indigo digital presses.

By the way, both Hexachrome and Indichrome also allow you to faithfully reproduce a lot more spot colors than traditional CMYK. But it's also true that for many standard images, hexachrome doesn't make a huge difference. On the other hand, for some images, a six color process can be quite dramatic. The value of six color processes depends a great deal on the subject matter being printed.

To date, it does not appear that many print buyers are willing to go to the added expense of hexachrome (HP calls their version IndiChrome). It will be interesting to see if IndiChrome takes off, since the digital process does not require extra plate costs. Although the system was announced a year ago, it's just now starting to become available from HP Indigo printer service providers.

Stephen Beals is a digital pre-press manager and has been writing for major print publications for many years. He is the author of A Practical Primer for Painless Print Production. He can be reached at stephenbeals@mac.com.
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