z3100 problems with banding, app managed color

[NedOtter]

Greetings to all --

As a recent owner of a z3100 44", I've been putting it through the paces for about the last 10 days. I have read numerous posts in this and other forums about banding issues on HP Pro Satin paper, but no combination of settings has worked for me. I came up with a workaround, but it's not optimal

I thought others might be interested in the email exchange I had with HP tech support.

I wrote:

"i am printing on HP professional satin paper with the gloss enhancer turned on. i am printing grayscale images scanned on a drum scanner, and the images are quite large, for example a 2 1/4 negative scanned RGB @ 8000 dpi, and the resulting file size is about 1 GB.  when i convert to grayscale, the file size is ~600MB.

when the image to be printed has large dark areas and i select  "application managed color", i can see bands across the print that are quite distracting. i then tried "printer manages color", and although the output was much, much darker, the bands were not present. i had to brighten the image severely, and then i got a good print with "printer managed color"

i have tried countless ways to solve this problem, but to no avail.
here are some of the steps i took, in addition to initially updating the firmware and other HP software:

1. cleaned the print heads, both manually and automatically
2. calibrated the printer
3. re-calibrated the paper
4. created/installed a new ICC profile for the paper
5. cleaned the optical drop detector inside the printer
6. calibrated the paper advance

thanks very much for your help."

HP wrote:

"Hello ,
Thank you for contacting Hewlett-Packard's Commercial Solutions Center.

We understand that you have noticed banding on dark areas of grayscale prints from your Designjet Z3100, which you have been able to resolve by lightening your images and selecting Printer Managed Color in the driver.

Because you have arrived at the same solution as we would have if we had been troubleshooting your issue with you, we really cannot offer any further advice regarding this issue.

Should you experience any further issues, please remember to calibrate for the paper on which you are printing, create an ICC profile if one does not already exist, try turning off gloss enhancer if using any non-glossy paper, clean printhead and carriage contacts, and check expiry dates and usage of all inks."

I have the banding issue on all types of grayscale prints, both light and dark, but of course it's more pronounced on the darker images. I have tried just about every conceivable setting in the printer driver, including Best and Normal, More passes checked and unchecked. Nothing I have tried so far makes any difference, and I find it hard to believe that HP expects those of us in the grayscale world to apply extreme levels of brightening to images we must print on their equipment.

All feedback is welcomed --

Best wishes,

Ned Otter

[Ernst Dinkla]

Greetings to all --


All feedback is welcomed --

Best wishes,

Ned Otter
[a href=\"index.php?act=findpost&pid=125690\"][{POST_SNAPBACK}][/a]

Using greyscale in the printer mode with or without Advanced B&W ?


There's no indication from which application the printing is done. You didn't mention the direction of the banding. The profiles you use are custom made or the HP ones for the paper you use? You are aware of the recommendation by HP to print with application CM off if the "advanced" B&W mode of the driver is used ? The printer runs continuously: it doesn't have to wait for data at some points ?

The original film is B&W or color film ?  It is drum scanned to RGB as mentioned and then in what way converted to greyscale: color channels in PS ?  How much is the print enlarged " In other words is there any sign of small banding in the greyscale file itself, how slight it may be if it falls in a shadow area that gets a stretched or compressed tone range for one reason or another (CM: perceptual + BPC) it may show there and not in another CM treatment.

If you use a greyscale 21 step wedge image in two versions 2.2 Gamma, 1.8 Gamma assigned and select either AdobeRGB or sRGB in the printer's CM + AdvancedB&W mode at its default, application CM off and print the two. Do you still see banding and which print gives the best tonal range, c.q. is not too dark ?

Ernst Dinkla

www.pigment-print.com

[NedOtter]

Hi Ernst,

Thanks very much for your help, and sorry I didn't post my complete scenario.These are the types of questions I would have expected HP to ask.....

I am not using Advance B&W. I am using the profiles created the the z3100, specific to the paper I am using.  

I'm using Photoshop CS2 on a PC.

The direction of the banding is horizontal, across with width of the paper. When I first started to print my images @ 16 bit, 8000 dpi, the printer did indeed have to wait for data, and prints took a very, very long time to complete. I then tried to make the image the proper physical dimensions, and this seemed to make the printing go faster. I also tried 8 bit files, and this seemed to help a bit, but was still unbearably slow.

The original film is B&W, scanned to RGB, and then converted to B&W using photoshop color channels. I have always select sRGB when using the printer CM.  The print is enlarged 1200 to 1500%. The image in question is from a 6x6 negative.  I have not seen any banding in the file itself, in either the light or dark areas.

I will try printing the greyscale 21 step wedge.

Thanks for your help --

Best wishes,

Ned Otter

[namartinnz]

I would suggest making a test print of the print head patterns. You may well have a faulty print head. I've had to replace 2 the photo black/light grey head twice now - both under warranty.

Neal

[Mussi_Spectraflow]

First off in the quality mode use the advanced settings and make sure "Best" is selected. Printing on normal is almost sure to result in banding. Other than that you should not have to do much else to expect banding free prints. Did you do a paper feed calibration...that is an important step. There's a remote chance that if your plugged into a very noisy power line that could affect the prints but I haven't seen that issue in a while.
On another note you may want to save a print version of your image in 8 bit mode, this will speed up the processing time a lot. 16bit is great for archiving but offers no real advantage in print...(please this is not an invite to get into the 8 vs 16 bit debate  ) How big are you printing these BTW.
Secondly I think the advise in the letter you got from HP is BS. This is not the best they can do. Printing from PS, choosing the correct ICC profile and rendering intent and then choosing application managed color in the printer driver, as well as making sure that the correct paper type is set in both the driver and the printer front panel is my recommended workflow. You shouldn't have to adjust you prints to math the printer, that defeats the goal of color management. Granted you need to make sure you monitor is profiled and look closely at the files. I have many negs scanned on the nikon 8000 that have banding that is often only visible in print. Zoom in 100% and look at the blue, and possibly the red channels.
Hope this helps.

Julian Mussi
www.spectraflow.com

[NedOtter]

Thanks for the advice Julian - I really appreciate it.

Quality mode of Normal or Best makes no difference regarding the banding. Yes, I did do a paper feed calibration.

And I have tried both 8 and 16 bit versions of these images, and the result is always the same: Application Managed Color shows banding, while Printer Managed Color does not.

I am printing drum scans from 2 1/4 b/w negs, 24" tall and 44" tall. The banding appears on prints of both sizes.

I have indeed zoomed in and checked the channels, pre-b/w conversion, and there are no issues. If there were, then why would the Printer Managed Color workflow be successful?

Frankly, I am at a loss to understand what's going on here. The next thing I will try is to print from the original RGB scans.  

Thanks --

Ned Otter

[rdonson]

Ned, I'm not sure what's going on either.  When I print B&W though I always choose "grayscale" in the print driver and use "Printer Managed Color".   Like Ernst says I then use the "Advanced B&W" for any alterations.  

I think I read somewhere that HP recommends this approach when printing B&W.

[neil snape]

Ned, I'm not sure what's going on either.  When I print B&W though I always choose "grayscale" in the print driver and use "Printer Managed Color".   Like Ernst says I then use the "Advanced B&W" for any alterations. 

I think I read somewhere that HP recommends this approach when printing B&W.
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Unless you are toning the prints printer color managment for B&W's is by far the best. In this way no ICC profiles are used and direct LUT's are used. I agree that for this printer you might want to save out a flat version in 8bits before sending out to the printer. I just printed a solid background of Orange, and on fast there was substantial banding. I thought since it was a solid there was no reason for using normal or Best. I reprinted at normal and there were no banding problems.
Don't hesitate to run a tiny crop of your image at 8 bit , even try downsizing PPI settings to 150 ppi. I cannot print from Mac at 300 ppi on large plots. Normally printer color management will produce a lighter print than a custom profile.. I keep going over your post but nothing is glaringly wrong. The possibility of a bad head sound okay until the fact it doesn't do this on PCM.

[NedOtter]

Thanks to all who have tried to help me with this issue.

Today I did further testing, and thought I would share my results....

I printed a color image that was about 60MB using  Application Managed Color, and had no problems with banding or speed. This was on matte paper.

Attempting to print a 650MB RGB version of one of the original scans on HP Pro Satin paper, the slowness issue appeared. The spool file was about 815MB, and it took forever to print a small section, with the print head moving to the left side after a few passes, and the re-aligning of the print head on the right side after a couple of passes. I didn't let it print long enough to see if the banding issue was present. I was attempting to print a 20" x 30" image.

I then printed a Printer Managed Color version of the same image, having converted it to b/w. The spool file was about 250MB, and it printed with no quality or speed issues.

I spoke to a tech resource at the company that sold me the printer, and he thought that since I was attempting to print grayscale images with App Managed Color, that it was forcing yet another conversion to color, and that this might be part of the problem. But then why would there be an issue printing an RGB version of the same image?

Thanks in advance --

Best wishes,

Ned

[Charles Gast]

with the print head moving to the left side after a few passes, and the re-aligning of the print head on the right side after a couple of passes. [a href=\"index.php?act=findpost&pid=127325\"][{POST_SNAPBACK}][/a]

Ned,
I don't think its realigning the print heads when it goes off to the side between passes. I think it is spitting ink in an attempt to clear non-working nozzles. I was having the same problem. I was lucky that a head cleaning fixed the problem. It may be that the print file size is only a part of the problem but the heads going off to the sides to dance a little jig between passes was a head clearing attempt. Even if you can print a good pattern it could be that the printer is using alternate nozzles to fill in for the non-functioning one(s) and then it tries to clear them the next chance it gets which is between passes. Kind of sounds like a bad printhead. I never knew which one caused my problem since even though the printer can detect failed nozzles and compensate on the fly it does not tell the user which one(s) are acting up unfortunately.

Charlie

[rdonson]

Ned,

I'm not following.  Why are you trying to print with app managed color?  B&W images (even RGB) are best printed by using grayscale in the driver and letting the printer manage color.