K7 Neutral ink change color shift and density issues

piezography

#1

(Using Epson 7890, K7 Neutral Inkset, Hahnemuhle Museum Etching)

Hi Dana,

I’ve refilled (or topped off) some cartridges with some new bottles of ink with the same SKU as the the ink that I had already been using, and now my prints are coming out more dense and have a horrible color shift away from neutral to Blue/cyan. I’m actually shocked at the difference. I’m starting a print edition (which could contain ultimately around 1,000 16x20" prints) and wondering if this is a mistake… What’s going on?

Even the ink in the bottle (#7 N) looks like it has stained the plastic a blue/cyan color.

Also, I’ve been under the assumption that these inks are made with all carbon pigments. Am I wrong? What causes the blue/cyan?

Thanks in advance for the help!

Ryan Boatright


#2

http://www.inkjetmall.com/tech/content.php?152-How-to-attach-images-to-this-forum


#3

[QUOTE=Jeffg53;8525]http://www.inkjetmall.com/tech/content.php?152-How-to-attach-images-to-this-forum[/QUOTE]






#4

The colour in the bottles has been discussed before:

http://www.inkjetmall.com/tech/showthread.php?1425-Piezography-SE-K7-MK-Neutral-Shade-1-Neutral-Shade-6-BLUISH-HUE-in-bottle-carts&highlight=blue

but there aren’t any reports that I’ve seen of prints coming out blue.


#5

[QUOTE=Brian_S;8527]The colour in the bottles has been discussed before:

http://www.inkjetmall.com/tech/showthread.php?1425-Piezography-SE-K7-MK-Neutral-Shade-1-Neutral-Shade-6-BLUISH-HUE-in-bottle-carts&highlight=blue

but there aren’t any reports that I’ve seen of prints coming out blue.[/QUOTE]

Great, thanks for that link. Interesting, indeed. It’s good to know that this is “normal”, although it doesn’t change the fact that I lost consistency by changing and topping of inks. That worries me. (not intending to sound negative here, just concerned). Also, I do notice a shift (density and color) in my new prints away from neutral to bluish/cyan tint. (note: I’m currently using Hahn. Museum Etching)

I do shake my inks weekly, and the machine has been running regularly recently. If it doesn’t get used for a week or two I run heavy cleaning cycles. I’m attentive and realize that the pigments need to stay mixed and suspended to obtain optimal results.

Are others getting inconsistent results after changing inks? Should I consider it to be apart of the process?

Also, is it possible to obtain more information about the composition of this ink set?

Thank you!


#6

What you’re apparently seeing in the bottle is supposed to be normal, but in my view what you’re seeing in the prints and describing about changes in print toning from just topping up the neutral inks does not seem at all normal to me. But I don’t use a large format printer for piezo and I don’t print on Hahn papers all that often, so it’s hard to comment further. There was a bad batch of shades 6 & 7 about 5-6 years ago that had a blue cast. But “that was in another country and besides, the wench is dead”, i.e. it was quite some time ago and you have a blue cast in darker tones.

IJM will want to know whether you’ve had colour inks in this printer before, because colour casts from residual colour ink in the lines and dampers is a common issue after a conversion. They will also want you to print the ink separation chart in calibration mode and measure it. I think they will want the values at 60%, if I recall correctly. They will probably want the batch numbers for each of the new bottles of ink.

p.s See these posts for another user who was having (different) ink issues and see what information was asked of him to diagnose the issue:

Request: http://www.inkjetmall.com/tech/showthread.php?1461-Dark-prints-and-posterization&p=7606&viewfull=1#post7606

Response: http://www.inkjetmall.com/tech/showthread.php?1461-Dark-prints-and-posterization&p=7650&viewfull=1#post7650


#7

I’m going to venture to suggest that the hues observed in the bottle as discussed in the thread http://www.inkjetmall.com/tech/showt...highlight=blue are caused by something different than what caused the hues observed on Boat200’s prints. If I interpret IJM’s explanation, the blues were due to light scattering of the encapsulated particles themselves, not the pigment colour. As the largest particles settle out, that would leave smaller less dense particles in suspension. These particles would scatter light in the same way the fine particles in glacial water scatters sunlight to create the blue light in glacial fed lakes. Because the printed image is not an encapsulation in suspension, there is no scattering, therefore I don’t believe this blue/cyan shift can be explained this way.

Larry


#8

1st we need to determine, why your image is so much darker then previously, this shift should not have been this drastic after topping off carts. Now to cover the bases here, we have seen shift of density in just about any ink set due to stall drivers or after updates to drivers in these Epson printers, it is not uncommon and the 1st line of defense is to Remove and Re-install your print driver, as well as your QTR driver. After doing this, please print out an Ink Separation through QTR Calibration mode and post to this thread so we can view your shade placement and output, you can find the instructions here http://www.inkjetmall.com/tech/content.php?144-Print-Ink-Separation-Image-thru-QTR-Calibration-Mode

And, for the color cast, how long was your printer run with pigment inks before switching over to K7? Was your printer Flushed out using Piezoflush before installing the NU K7 inks or did you chase the color out with the K7 and how long ago was this conversion made?


#9

Thanks for all the thoughtful responses!

I have never changed or updated the drivers since I got everything running smoothly 2 years ago. I’m using a windows machine that’s only used for this purpose and never gets updated. I’ve learned after some time that updating systems and drivers often causes more headaches than its worth! Now I never update things, and will dedicate a computer to a machine, if needed.

I changed over my machine for piezo around 3 years ago, without flush. But… It did take some time to get rid of the color cast. After discussing with Inkjetmall, I had to run additional power cleanings, and the problem was solved. Neutral prints from then on out. I was starting to feel confident in the consistency of my system :slight_smile:

In general, I’ve been printing more and more Piezo for my clients, and everything was rather stable- density, neutrality, etc. After I refilled or topped off the inks (some carts had dropped to about 30% levels) I did do a power cleaning. I had just printed that image the day before adding the new ink (opened a couple of new bottles for this- noticed the color of the ink in the bottle shade 6, in particular, seemed strange, after seeing the drastic color shift of my print). The machine had been giving me consistent results for months, until bam… Things changed. I was right in the middle of making an edition for my client. I tweeked the curves and essentially explained there was nothing I could do about the color shift.


#10

Do you have a measure device to test Lab values? If so, it would be very useful if you could print an Ink separation through QTR calibration mode, instructions found here, http://www.inkjetmall.com/tech/content.php?144-Print-Ink-Separation-Image-thru-QTR-Calibration-Mode
on any of these 3 papers so I can determine if your values are on track with ours: Type5 w/Go, Type2 OR HPR

This will also show us if your ink shade placement is in the correct positions, after printing the Ink Sep. please post a picture so I can compare as well.

Sometimes drivers go stale for no reason what so ever, I have seen it happen time and time again. And when they do, the shift of density is normally a drastic one. It’s a VERY simple test to do just to verify it’s not the problem. You remove the epson & QTR print drivers and then re-install, including your QTR install for your printer.


#11

Hi Kelly,

I’ll try to get some measurements and photos to you asap. We’re moving studios and will be in construction mode over the next couple of weeks.

I understand that you’d like to isolate the problem, but I am very suspicious that the new ink is very different (easy to see the color in the bottle which I had not noted before, which matches the color shift of my print). Up until the change, everything has been really consistent and neutral.

Just FYI… I make my own curves, and the positions of my inks haven’t changed.

Thanks so much,
Ryan


#12

Hi Kelly,

I did the print test this morning, and compared it to another that I had done a few months back. It’s really interesting. Actually, my measurements are showing that the color is actually more neutral. I’m now confused!!! Yikes
Perhaps I was used to seeing it too warm before and associating that with “neutral”? I’ve installed the piezo system around 3 years ago, although I have perhaps only used 1-2 sets of cartridges through it in that time. Work is just now picking up with piezo at our studio. As I mentioned, I didn’t use the flush carts in the beginning, just ran a bunch of hard cleaning and normal cleaning cycles, thinking that everything was cleared.

Check out the measurements and let me know what you think. The comparison photo has my old measurements on the left and the new on the right (printed today). The full test page was just printed today.

Thank you,
Ryan





#13

Ryan,

Keep the inks shaken regularly including within the cartridge. The inks are encapsulated and will re-suspend nearly instantly. Color inks also fall out of suspension but most eyes are simply not sensitive to notice tens of thousands of color changes in a print. Humans just can not process that many delta E differences simultaneously. But, with monochrome you see instantly.

We shake our inks in the printer or cartridge every couple weeks. If we allow a printer to sit for several weeks - we either INIT FILL or use 3 Power Cleans (on older models) to bring freshly shaken ink to the print head.

Jon


#14

From the looks of the LAB values, this is a case of settled pigments causing your color changes to be so drastic in some of the shades (such as 3,6,7).
After taking Jon’s advise, perform this test again and see if the values come closer to where they were a few months ago. A range of +/- 1.0 is acceptable


#15

[QUOTE=KellyC;8782]From the looks of the LAB values, this is a case of settled pigments causing your color changes to be so drastic in some of the shades (such as 3,6,7).
After taking Jon’s advise, perform this test again and see if the values come closer to where they were a few months ago. A range of +/- 1.0 is acceptable[/QUOTE]

Thanks Jon and Kelly. I’ll give the print test another try after shaking the inks well and then doing an initial refill. It will be good timing- we’re right in the middle of moving studios, so the printer will have set for a good 2 weeks without use by the time I get it up and running again.

Best,
Ryan