Odd Color Shift On Hp 360

[CountyDown]

We are experiencing a very frustrating color change.

Printer HP 360
Media Dreamscape Mystical
16 pass

See attachment

We are at a loss to explain this. The file has been checked for clips, hidden boxes etc, but there is nothing there......If anyone can help, I would be grateful..

 

[dypinc]

Do you have the ability to rotate the file 90 degrees?

Other thing to test is use CMYK only. At 16 pass it should not be ink starvation of the one lc/lm head but maybe that is the case. What ink density?

With the texture on the media the lack of using lc/lm might not be noticeable.

 

[CountyDown]

Do you have the ability to rotate the file 90 degrees?

Other thing to test is use CMYK only. At 16 pass it should not be ink starvation of the one lc/lm head but maybe that is the case. What ink density?

With the texture on the media the lack of using lc/lm might not be noticeable.

Yes we rip through onyx, and we have been rotating alternate panels anyhow....I will try the cmyk idea...do you think the lc is causing this?

 

[dypinc]

I don't know if 180 degrees would make much difference but if I am assuming that the green is printing after the solid purple, what happen if the green prints before the color change. If the solid purple prints first, check and see if the darker purple matches where the purple starts.

I have seen this on lower passes where lc/lm inks were used but slowing up the printer seemed to minimize this issue. That is why I am surprised that it is showing up at 16pass. But maybe real high ink densities would cause the same issue at 16pass.

 

[dypinc]

One thing I forgot to mention is that HP has advised to add Inter-Pass Delay for this issue. It works well at lower passes. I know you probably don't want to print any slower but it is worth a try as well without resorting to not using lc/lm inks.

 

[CountyDown]

We tried the delay as well, but it was just the same. And no matter how we rotate the file, the line still appears. This green/blue area was originally a tan/brown color and there was no problem. It was only after the client requested this bright primary color that this started. All other areas of the file are fine, it only happens where these bright shapes appear.

 

[CountyDown]

I tried the same file on a flatbed OCE 6170, and it shows there too. This would make one think its in the file, but it has been checked bu numerous people and its fine. There seems to be some difficulty that printers have reading two extreme colors..

 

[ikarasu]

I'd bet more it's onyx, and not the printers.

HP came with a free copy of a different rip, did it not? I'd install that and try. I know our older onyx version gives us a ton of issues, so if yours isn't the newest I'd consider that.

You could also try to rasterize the file and print it that way.

 

[Bly]

I used to notice the same thing on our old HP5000s so it's not a new thing.
Never worked out how to prevent it though.

Hows that 6170?

 

[dypinc]

Here is a clear indication of the issue which still puzzle me why HP will not rectify this problem. I don't remember seeing this on the L25500 which had two lc/lm printheads.

This job came in today. Large sign that did not need CMYKcm and I wanted to print at 10pass. I also recognized that this issue would probably show up if using CMYKcm. Like most jobs of this nature I always use CMYK unless it is POP signage that needs less graininess. During printing I remembered this thread and wondered would it show up if I used CMYKcm with the preset set for 200 inter-pass delay. The gray combination border was 4' across and you can clearly see the results. Output profile black generation was set to start at 30% so lc/lm was being used heavily to create the light/medium gray.

 

[dale911]

That line is so defined and follows the green as well so I believe it's the file. I had a file similar on a banner that looked fine and everything was well until I printed it. I assume it's a PDF. I would resave that file as a jpg and let Onyx rip that and see what happens. It has something to do with the way it's seeing the layers in the PDF even though everything looks right.


Sent from my iPhone using Tapatalk

 

[tylercrum]

Yeah, that's not a printer issue. That's a "design software / rip" issue.

 

[dypinc]

Yeah, that's not a printer issue. That's a "design software / rip" issue.

Not likely. It shows up in CMYKcm mode but not in CMYK mode. I have seen this many times. Defiantly a flaw in the L300 printers be it ink starvation or some other problem.

 

[jayhawksigns]

Not likely. It shows up in CMYKcm mode but not in CMYK mode. I have seen this many times. Defiantly a flaw in the L300 printers be it ink starvation or some other problem.

That's a concern when looking at picking up a L560, since it shares so much with the 360. Sure its something you can adapt to (using CMYK) but that's adding a bit to setup. That;s fine when I am here, but when I leave for a week or two at a time and others in the shop need to be able to use the equipment, its a lot more of a hassle.

 

[joelthomas]

The problem is similar to ink starvation. The printer goes for a while without exercising some nozzles then when it's called upon to use them it takes a few passes for them to prime up.

Two possible solutions.

1. On printer go to Settings-Image Quality-(bottom of list) "Color and small text". Cannot remember exact name. Turn this on.

This adds a very small amount of noise throughout the print. It basically fires a single drop (picoliter in size) throughout the print the keep nozzles primed. It's only noticeable if you use a loop and look in white area.

2. In Onyx -layout options-gutters turn them on.

Similarly, this feature fires all the jets down the side of the print keeping them primed so when it gets to the area of green the heads are primed.

It probably didn't show when the color was brown because the same colors used for brown, are used for purple.

 

[dypinc]

Interesting idea but that doesn't account for my samples I posted previously.

The same gray border with the same nozzles firing there is a difference when the 4' of gray was printing and when only 4" at the side was printing. This shows up both at the beginning and at the end of the print. And the lighter area is always where more ink is being laid down.

And, if the lc/lm printhead is not being used it doesn't show up.

So how would the Gutter option help in this situation since around 4" on both side are being printed firing the nozzles?

And remember in the Purple Green sample, some amount of the Purple has been firing all the time. Keeping the nozzles primed?

One possibility is that I have a bad lc/lm printhead but all tests do not show any issues and it shows around 2,000ml used.

 

[Correct Color]

Just an aside that as I look at it, and as I poke around at it just a little in Photoshop, what it looks like to me is that the main issue is a difference in magenta on either side of the line. And since the magenta is obviously printing at well over 90%, that would seem to me to kind of rule out an issue with the light ink printheads, since the light magenta would not be firing at that density.

 

[dypinc]

I my samples of the light gray, if the lc/lm printhead is not being used it doesn't show up. With the purple since we don't know the light link splits we don't really know.

I would love find a reason for this other than the lc/lm printhead but I can't.

 

[tomence]

That's HP for you, I have been dealing with this same problem for years on my L260 but since I can't seem to find what's causing this problem either software or hardware I have learned to live with it and hope for customers to not notice the color shifts.

 

[dypinc]

That's HP for you, I have been dealing with this same problem for years on my L260 but since I can't seem to find what's causing this problem either software or hardware I have learned to live with it and hope for customers to not notice the color shifts.

So on the L260 does eliminating the lc/lm inks correct the problem like it does on the L300s.