Colour Managing HP Indigo

[bee]

Hi

I've been charged with the task of trying to get some colour management happening on a HP Indigo. I've printed some ECI charts, but am finding that the black channel is going negative in the highlight when looking at the dot gain.

I have had limited info on how it works, and am trying to find some more. Does anyone know much about them as far as ability to calibrate, colour management options, and separation settings that are suitable for making a profile for this type of printer.

I've been told that there are some preset 'profiles', but the fact that the black channel is dropping out in the first 10-15 percent of dots indicates to me that maybe the machine itself has problems?

Thanks, Bee

 

[LoneGoose]

Re: Colour Managing HP Indigo

I've no experience with the Indigo specifically. But, for a digital press, an aggressive GCR seperation might be prudent. Electrophotography is not known for it's stability in colour reproduction - I'd average several charts.

Doesn't the Indigo have six or seven colours? Are you going to generate a custom chart for it?

 

[meddington]

Re: Colour Managing HP Indigo

We've got an Indigo 5000 here (4/c process inks, plus up to 3 additional). and I've actually found it to be a pretty stable device compared to say offset and toner based devices. I would still recommend robust GCR in your separations though, despire no monetary benefit from reduced CMY ink consumption. It does tend to drift color wise and this will minmze the shift.

I also found the default LUTs give a somewhat weak appearance in the highlights. This is something that can be dealt with though. You can create new LUTs for each separation to get the desired dot percentage upon output. You can create and save them in the Color Control tab of a job in the queue. Then you can edit your ticket template to use your new curves instead of the default curve (EXP-05 I believe).

As for what values to aim for for your LUTs, you might try applying the G7 methodology (www.gracol.org) as an aim point for gray balance rather than hard dot gain values. Or, if you have a press you're attemptng to match, you can aim for those dot gain values (or adjust both toward G7). For consistency, run frequent color adjusts and Lut Generations to rebuild your settings.

 

[degolf]

Looking for more G7

Looking for more G7

Hello

Looking for more detailed G7 Lut curve application utilizing Curve2 to generate the curves and applying them on press. We then do a profile on top of this for final color control.

Thanks

David Egolf

 

[exchief604]

Watch the age of the blanket

Watch the age of the blanket

When ever you are setting color on the Indigos be aware of the age of the blanket. When you first put the blanket on it prints different for the first thousand or so clicks. It then has a sweet spot for the next 25000 to 30000 clicks depending on the work running on the press. Then the hi light dot is the first to taper off. The blanket looses its ability to hold the proper charges and transfer the smaller dot first.