Maximum black CMYK (ink saving)

[andy1]

Hi guys,

I've just bought a digital press and as you're probably aware the cost of toner, especially colour is silly, even when buying compatible toner.

I had a look on wikipedia a while ago for some information regarding CMYK and RGB differences, but I came across an article that mentioned "maximum black" as a CMYK composition, using this method significnatly reduces the amount of colour toner used. My press is a Xante Ilumina and from what I can tell it likes to use CMY with a touch of black wherever it can get away with it, creating phenomenal toner costs in the long run. Does anyone know how to get Illustrator - or any other software app - to change CMYK settings to "maximum black"? This wouldn't be much use for Pantone matching but for general printing it could be useful.

The wikipedia link is below, the CMYK breakdown is half way down the page.
CMYK color model - Wikipedia, the free encyclopedia

Any advice would be greatly appreciated,

Andrew C

To update anyone following this: Being new to digital printing I didn't notice the difference between PCL and PS drivers. PostScript drivers send the exact CMYK settings - when stored - from PDF, AI, EPS, etc...documents and produce whatever colour you tell the printer to, i.e. 100% K as I indicated above. A good composite on the Xante/OKI machines is C50 K100, at a push C100 K100, do not mix magenta and black without cyan or you'll end up with a pink or dirty looking print.

 

[mattbeals]

You need GCR, Gray Component Replacement, or UCR, Under Color Replacement. The ICC profile you are converting from RGB to CMYK would need to have UCR or GCR built into it at the desired leve. Or you need to use a device link profile to convert one CMYK into the same CMYK or a different CMYK. When using a device link profile you can specify how much, or how little, GCR you want to use.

 

[andy1]

Thanks!

I don't know what a link profile is, but I'm sure I'll be using colour profiles soon (I used inkjet for 4yrs, where colour profiling was all automatic). I'm guessing printing directly from Illustrator to the printer, after defining the CMYK settings myself will do the job then. My only issue at present is printing photos obtained from various sources, should Illustrator standardise them as the profile the .ai or .pdf is saved as?

Thanks,

Andrew

 

[mattbeals]

Well, that's a pretty big question... First, not all devices print well using GCR. Xerox iGen's I have been told do not "like" GCR and print better with UCR. Both UCR and GCR do similar things in different ways. A device link profile directly "links" one ICC profile to another. Rather than converting from one CMYK into RGB (or LAB) and back to CMYK.

It's not a problem to have multiple color spaces on a page and convert them all in Acrobat to one common CMYK space. It may be easier for you to always convert all the elements to one common CMYK space before making the PDF or AI file. It may be more convenient to have Illustrator convert all the elements to one comon CMYK space when making the PDF.

Like I said, it's a big question. There are lots of ways to achieve the same result. The question is "which way works best for you?".

 

[andy1]

Thanks very much, I'll have a play with Illustrator and see what it comes up with.

Andy

 

[TerryWyse]

Thanks very much, I'll have a play with Illustrator and see what it comes up with.

Andy

Andy, I would avoid dealing with this issue (re-separating to increase GCR) in your applications and see if you can't deal with it in the front-end (DFE) of your digital press. Most DFEs have ICC color management built-in or at least as an option. The better ones will allow ICC device links as well. If the only thing you want to do is decrease the amount of CMY toner via GCR and not really "color-manage" your documents, it's pretty straightforward to do that by simply creating two profiles from the same data set such as GRACoL Coated1 or SWOP Coated3 but increasing the amount of GCR in the profile you plan to use as the "destination" profile. By creating the profiles from the same dataset/measurement data, you'll avoid getting a "color-managed" transform that could mess with the colors and simply get a conversion that re-separates for more GCR.

Depending on your volume, converting your application files in their native applications upstream of your digital press is going to be very time-consuming and not seamless at all in my opinion unless you have a way of automating this. Even if you don't have the ability to use ICC profiles and device links in your digital press DFE, there are other ways to completely automate the conversion.

Regards,
Terry

 

[andy1]

Hello,

Thanks, most of this is beyond my knowledge at present. Once the press is fully operational I'll see what I can do with the colour profiles, at the moment I can't use the printer to experement as it isn't setup properly.

The press is a Xante Ilumina 'laser' printer, but the quality compared to any other laser I've seen is phenomenal, however it isn't up to HP Indigo or Konika Minolta specs. Still a cracking machine for small runs of cards and stationery though...but as you say, volumes won't be an issue and a labour intensive process isn't going to cause much trouble at present.

Many thanks,
Andrew C

 

[srawding]

a labour intensive process isn't going to cause much trouble at present.

Editing files opens you to introducing error. Put effort into exploring Terry's suggestion. You don't need the grief.

 

[andy1]

Hello,

I certainly will do, once the printer is in a state where I can get to it easily and actually have a permanent computer setup I will get some colour profiles setup. I'll use the free RIP software Xante provide, and the ColourMatch software included with the printer.

I actually offer free design services to most regular customers, so that solves most problems, and after importing an RGB image into Illustrator I discovered it successfully converts it into CMYK, although it doesn't maximise the K value.

Thanks,
Andrew

 

[TerryWyse]

Hello,
... after importing an RGB image into Illustrator I discovered it successfully converts it into CMYK, although it doesn't maximise the K value.

Of course it won't Andrew...you have to build "special" ICC profiles where you've purposely increased the GCR and K generation. You didn't say what profile you used to convert to CMYK, but the chances are it was using a "standard" level of GCR. If it was "US Web Coated (SWOP) v2", it has very conservative GCR/K.

If you want to see an example of what can be done, send me a sample file that I'll convert using a "normal" CMYK profile (I'll use GRACoL Coated1) and then convert it again using one where I've increased the GCR and then you can compare the two. If your digital press can report ink/toner usage, you could do a short run of the two files and compare toner usage from each run and do the math yourself.

Terry

 

[andy1]

Just a quick update...

Been running a few long jobs off and weighing toner pre and post print and the colour profiles that come with the Ilumina work very well at maximising black. I've been printing with approximately 10-15% less toner usage than APFill predicted so all is well so far.

Thanks again for your help,
Andrew C

 

[tsdomenichelli]

Hello All,

Does anyone have a list or a document that says how are setting the GCR and UCR into a "standarts" ICCs profiles?

Any information will be apreciate.