Achieve Rich Black through RIP

[zamajam]

Hello! Our clients send in files all the time with vector solid blacks that are 0/0/0/100. When we print those we get streaks in the black areas. We then go into an editing program (such as Illustrator) and change those blacks to 40/40/40/100 (a color that seems to work good on all our presses). I was wondering if there was a way through our RIP (Caldera GrandRIP+ v9.2) so we do not have to open every file to check the blacks. Also, is there a way to set the RIP so that each file we send through it will automatically change all the 0/0/0/100 blacks to 40/40/40/100?

Thank you for the help!

 

[Stephen Marsh]

Are these presses inkjet based, toner based or traditional offset presses printing separations from plates?


Stephen Marsh

 

[zamajam]

They are all inkjet based.

 

[Stephen Marsh]

Are you using “standard” device ICC profiles in the RIP or “DeviceLink" ICC profiles?

Either way, I would expect the output to use a rich black…Is there a RIP setting to preserve the K channel data?


Stephen Marsh

 

[zamajam]

Are you using “standard” device ICC profiles in the RIP or “DeviceLink" ICC profiles?

Either way, I would expect the output to use a rich black…Is there a RIP setting to preserve the K channel data?


Stephen Marsh

I am using a standard device profile. There is a setting to preserve the K channel which we currently have disabled.

 

[Stephen Marsh]

My expectation is that a 0cmy100k source item would be transformed into a lighter rich black using a standard inkjet ICC profile.

My expectation is that a ?cmy100k source item would be transformed into a darker rich black using a standard inkjet ICC profile.

So your final output may indeed be rich black, however it may not be “dense” enough and thus “streaky”?

If you install the inkjet profile on a computer with Photoshop, it will be easy enough to verify the final device CMYK builds for incoming objects with a build of 0cmy100k or ?cmy100k etc.


Stephen Marsh

 

[zamajam]

I can't thank you enough for your help with this. I am going to install the profile on a computer with photoshop and see what it says.

Thank you again!

 

[Stephen Marsh]

I can't thank you enough for your help with this. I am going to install the profile on a computer with photoshop and see what it says.

Thank you again!

Not a problem, that’s why we have a great community here!

EDIT: Do you use a “target, simulation” profile to mimic an offset press colour, or do you print at the inkjet gamut? Is there a colour management option to define the source CMYK profile and rendering intent or BPC for incoming CMYK data (perhaps the issue is there)?

As you have different inkjet printers, you will have more than one profile (for each machine and media, resolution, no of passes etc).

I would setup a CMYK source file with an area of 0cmy100k and another area with 100cmy0k and another area at 100cmyk and another area with 50c40my100k. You can then use fixed colour samplers in Photoshop and the info window to compare the colour build before and after conversion to the inkjet device profile. When converting you may also wish to use the same CMM, rendering intent and or BPC as the RIP is using (or experiment with different options). You will also need to use the same assumed/assigned CMYK source profile as the RIP (ISO Coated, GRACoL, SWOP etc).

If you were using PDF workflow software such as Kodak Prinergy, then you could probably automate the fixing of 0cmy100k to say 50c40my100k during the refine process. You could even do the same for text and vector fills/strokes using PitStop Pro or PitStop Pro Server action lists.


Stephen Marsh