Out of Black, whip a CMY=K batch??

[mtygabriel]

Sounds crazy!!! I am almost done with a print job and cannot get black ink in on time from vendor. The black ink requirement is very little but the cartridge needs to have some in it.

Has anyone ever made a batch of black ink by combining a mix of CMY??

It makes black after all and it is the same ink. What do you think?

 

[Fatboy]

What model machine?
Inks might not mix properly.Not the same density.Maybe not

 

[mtygabriel]

Durafos SS221 Medium Solvent Ink. Are the pigment sizes different for the different colors within the same vendor?

 

[Fatboy]

yes definitely . You know,the more I think about it,rather don't do it. What do you other guys say?

 

[otctech]

I would think that the mixed black wouldn't be exactly the same as the black on any part of the job you've already printed. So if they're next to each other you would be able to see the difference.

 

[mtygabriel]

I am printing on canvas. This is a hotel job so each print will go in a different guest room. If the difference is suttle where you and I might tell the difference, it wouldn't be obvious if they are hanging in different guest rooms.

I can continue printing without the black because I have a bulk ink systems with the chips reset to 9 so it thinks there's ink. I think though that the lack of black might cause negative pressure and sucking some of the yellow next to it. Or that the print might look better with that black or near black addition in calls for however slight than not having any at all.

I guess the main thing is whether the pigments vary in size and if using other colors will clog the head due to it.

 

[mtygabriel]

Forgot to mention.... JV33.

 

[otctech]

If it works in head "1" and head "2" is the same style head, I don't see why it wouldn't work even if the pigments are slightly different.

On the other hand I could see the different pigments "clumping" together maybe???

Tough call.

 

[mtygabriel]

I had some "empty" 440ml cartridges laying around and sucked all the ink out of it yesterday with a syringe.

There is a little bit left on the other bulk ink cartridge but I don't want to stick the syringe into that one as it is the permanent cartridge on the machine.

 

[signswi]

In theory 100/100/100/0 will print black but it's a lot more ink on the material and will probably have some sort of color tint (especially solvent...).

 

[GAC05]

What RIP software are you using?
When I was phasing out my aqueous printer I stopped reordering ink near the end and black ran out first.
I then used the CYM print option (in Flexisign) to run several jobs.
It didn't pull any of the residual black ink out of the intermediate tank so the printer figured everything was fine. Output was not bad at all.
By the end of it's life my 6 channel printer was down to 3.
May not work for what you are doing but it could be an option.

wayne k
guam usa

 

[TheSnowman]

I thought I remembered Mike @ Merritt saying that they used waste ink as black...if you are running bulk.

 

[mtygabriel]

It's a branded version of ONYX v7. Hadn't thought about a setting but did a quick look around and didn't find where I could tell the RIP to use CMY. That would be a nice option.

We talked about using the waste ink. My only doubt was the additional Cleaning Solution that goes into it. Does it affect the mix? I do have liters of C M & Y and could just use them directly. But if waste ink is good enough, then good enough!!!


Both ideas above are great, specially the CMY as it would be in the RIPs hands to hit a nice black for the printing requirement.

 

[Mike F]

I thought I remembered Mike @ Merritt saying that they used waste ink as black...if you are running bulk.

Think I remember him saying that as well, in a topic where someone was trying to figure out how to disposed of their waste ink. Don't think I would do it personally, but I'm paranoid like that.

 

[National Sign Co. - Print]

We do it with waste ink on our XL jets. We also mix 5% pure K ink to give it more black and make up for the head flush/solvent in the waste also.

We also have profiles with black curves and densities up to compensate for mixture. I would not suggest trying a withcraft potion on a whim because you ran out of ink.

What we do has been formulated as a solution for our solvent production presses it works with. We do it to reduce our waste that needs to be disposed and also for obvious ink savings..

 

[Custom_Grafx]

Create a colour profile with no black or a really late black start? Sorry that's no help if you don't make your own profiles, but just a thought.

 

[mtygabriel]

Well with Lexjet having acquired my previous and possibly only supplier of Durafos ink, On A Roll Color, I may have to resort to experimenting with using waste ink in lieu of pure K black. I have a couple of liters of the other colors and I wan to use them up. This might be the best time to do it as I may already be looking at a new printhead anyway. I have a thread regarding my very faint yellow printing problem.

It appears from Merrits above that it is safe to put the other inks through the printhead dedicated for K black. In other words it appears the different ink pigment sizes are all safe to run on the black K nozzles. I was reading a document explaining the different chemicals used in making the different color pigments and their sizes, but nothing like a table showing size for each and nozzle limits. That would be interesting to know.