Macro-Banding - new 7880 printer with new inks

Hi there,

After all my misadventures with an old 9900 and Piezo Inks, I purchased a “new” 7880 (used, but only a couple of times) and loaded it with new fresh Piezo inks (Selenium, P2 system).
Based on my experience with the 9900, I corrected the Paper Feed Adjustment for the new machine and Pictorico, and eliminated all traces of micro-banding. The negs look great, and the first two prints were magnificent. BUT…

On the third print, with a blank uniform sky of tonality 27% (that, once inverted, gives in the neg a tonality of around 70%), I have noticed what I would call macro-banding, aligned with the direction of the printing head (that is, the lines are horizontal when you see the negative coming out of the printer). These bands are very uniform, of around 5 mm thickness (darker bands) and separated around 1 cm apart. There is no trace of microbanding, or other artifacts, but the sky, on the negative and the print, looks with very thick bands. The print is going to the bin, as it is unusable.

I am attaching here two images where the bands can be seen on the negative.

The printer has all the nozzles going well, and as I said, it does not microband.

What might be the culprit of these “thick bands”? At first, I thought they might be due to the rollers, or even to the suction bands… but as I said before, the bands run from left to right (horizontally), so they do not fit with this two hypothesis.

Please let me know what to do. My level of frustration is going through the roof. After 5 years of trying to get negs free of artifacts, first with a 9900 and now with a new 7880, it seems simply impossible.

Thanks in advance and regards,

Rafael

all you need to do is set the platen gap correctly and then do a manual unidirectional head alignment on the media that you are printing on.

best,
Walker

Hi Walker. Thanks for chiming in so quickly!
I have set the platen gap to Narrow right now. How to decide which platen gap to use?

I thought the banding linked to head alignment problems happens the vertical direction … not in the horizontal one like here?

Thanks

rafael

Oh, sorry, did not see that they were horizontal.

How fast is it printing? I may be stuck in 720dpi mode . . . looks like that to me . . .

re-install of QTR + printer + curves usually fixes.

-Walker

Hi Walker.

I am printing Uni-directional, with no drying time.

The resolution is 2880 dpi… What do you mean when you say it is stuck in 720 dpi mode?

I will try re-installing…

I have the impression this is not really printer related, but more software related? (dithering, etc).

Have you seen this kind of behaviour before when printing really homogenous zones?

Regards,

rafael

Really look at the print as it’s coming out. Is it printing really fast? Sometimes it gets stuck in 720dpi (software problem) even though you have set it to 2880 in the driver.

best

Walker

Hi Walker.
I tried resetting-reinstalling everything (QTR - Printer - Curves). The banding, when printing homogenous areas (like a blue sky in black and white) continues to be visible. Thick bands of darker tone, set apart 1.5 cm… horizontal.

There seem to be another array of vertical bands, these seem to coincide with the suction channels of the printer. They get reduced when I select Suction -4 and drying time of 6 seconds. I am using Standard Platen Gap. Narrow does not seem to make a big difference. The Paper Feed Adjustment was already controlled, and its banding (micro-banding) disappeared…

So, I am left with the horizontal banding, with unknown causes, and the vertical banding that seems to be suction-caused.

Have you got any suggestions about both banding problems? How do you guys print blue skies in platinum there at Cone Editions? I start to think that this might be a limitation of the inkjet digital negative system… or should I find a solution for my problems?

Thanks so much for your help, it is really needed since I am having an important display of platinum prints in two weeks and I need to produce! Please let me know if there is anything else I can do to test and try to find the cause of the problems here…

Warm regards,

Rafael

The only time I saw this issue was when it was printing very fast stuck in 720ppi. You have verified that this is not printing fast and is indeed printing 2880?

We print gradient skies all the time.

regards,
Walker

Hi Walker,

I have made tests today with areas of 70%K being printed in thirds of Pictorico 8,5x11" sheets.
I have printed at 720 dpi and 2880 dpi, and there is indeed a huge difference. At 720 I do indeed get small micro-banding, and the resolution is visibly lower, and printed faster than when choosing the 2880 (45 seconds instead of 3 minutes 45). In other words, I seem to have been printing all the time at 2880 dpi.

The horizontal bands appear still… a bit less when I select drying time of 6 seconds, but there nevertheless and visible on prints… What would you do? Is the only solution to get a new printer and start all over again?

On a side note, it is interesting to see however that micro-banding appears too when choosing lower resolutions (I tried with 1440 Super, and I also got microbanding). But, at 2880 dpi, the Paper feed adjustment setting that I calculated seems to work well, and all microbanding disappeared.

Thanks,

Rafael

FWIW, I have seen this exact same thing, with the exact same symptoms and it was equally confounding. In my case, it turned out to be faulty paper (!). Have you tried different paper?

Hi! Thanks for your answer. I am using it on Pictorico… and the problem persists even with different packages of film. So, it is printer-system related…I guess.

Rafael,

You sound like an experienced Piezography user but I will ask: are you using Pictorico ultra-premium OHP?

And there may be something specific to your environment (workflow, printer, etc.) that is causing the problem as with my 7880 with PiezoPro inks on ultra-premium OHP I have not see the issue you described. And as Walker pointed out CE prints sky gradients all the time without issue. However, it is obviously there and very frustrating. Have you tried printing the negative using the Piezography beta driver workflow?

I am also wondering have you made a print with this negative? Does the banding show up in the print?

Good luck!
Michael

Hi Michael,

Thanks so much for chiming in!
Yes, I have been using Piezography for quite a number of years… I would say that by now I have mastered the theory and the process… I am using Ultra-Premium, yes. I am also using a plateburner to expose, not black light tubes. This makes, as Walker and some other users of plateburners know, negatives quite loaded with ink. Maybe that is why I am seeing things and others do not?

Michael, have you tried to print a uniform band of say, 30% grey (that turns as 70% grey when printed with Piezography and PiezoDN curves)? I am now doing that test, and the bands I get (both vertical due to vacuum, and horizontal due to some unidentified problem) are clearly visible. It is nothing to do with nozzles (they are all firing well), nor platen gap (I have tried every setting, with minimal changes), nor paper feed adjustment (it has been adjusted - tailor made for the Pictorico paper through printing 100 cm long), nor head alignment (I had aligned with Pictorico paper), nor paper thickness (I have printed the test and settled with 0.2 mm). So, right now I have tried everything. The system is printing wonderful negatives when there are no areas of solid tone and plenty of detail. Fantastic prints. But when there is a sky, or smooth area of water, or similar… no way.

It is a pity. I have spent literally thousands of dollars on these inks and system, on two printers now, and I do not seem to be able to print a blue sky in black and white.

Walker, would you have any other idea about what could be happening here? Is this the kind of banding that led you to start developing the Beta driver? Could it be the dithering of QTR playing havoc here? The printer was used only to print 20 prints… it is virtually new, so I do not know what could be faulty in the hardware?
Could I give you a call to discuss about any possible way of troubleshooting this? Maybe talking we can find the reason, or at least decide on some things to do to rule out potential problems. I have another couple of printers, and I am tempted to try the Epson inks and Boutwell system, but I would really like to continue to use Piezography and PiezoDN curves…if possible.

Thanks in advance and warm regards,

Rafael

it could be useful to test with different ink overlaps as this printer does not seem to be happy with the current ones. But I really think it’s. more paper-feed speed, or head voltage issue, or combo. The issues with QTR in the past have been cross-hatch issue not what is photographed on this thread . . .

I assume you did a paper feed speed calibration?

-Walker

Hi Walker! Thanks for the quick response, I appreciate it a lot.

Yes, I printed the 998 mm test, and came with optimal +0,34% value for paper feed adjustment. Since then, all microbanding disappeared… the patches of targets for instance are really clean and uniform. It is when printing big expanses of solid tone than the bands appear. From print to print, they are not always the same thickness, nor display always the same distance, even if on a given print the will… I thought paper feed adjustment problems showed up as microbanding, not “macro banding”?

The voltage problem you mention, is it a problem related to a faulty head, or is that caused by the electrical installation in the space? Is there any way of testing if that is the cause, or what would correct such a problem if that is the culprit?

Thanks again. It is really frustrating this time, I am producing absolutely gorgeous platinum prints right now whenever there is no possibility for this banding to show up… but whole projects that I need to print display massive clean skies!

Regards,

Radael