Prints are too short - on Fine Art paper

[Stephen G]

I print with an Epson 9900 through Q-Image Ultimate. I'm well aware of the canvas 'shrinkage' issue and I'm used to compensating for it when using various brands of canvas.

I've been printing a run of large images on Hahnemuehle's German Etching paper and I've just noticed the same issue. The printed images are consistently about 0.3% shorter than they should be. Doesn't sound like much, but sometimes things just have to be dead right.

I know I can just compensate and carry on with life, but I wondered: has anyone else seen this on the same paper, or other fine art papers?

[Ernst Dinkla]

There usually is a length alignment test/control in the printer's utility software of wide format inkjets.

--
Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
April 2014, 600+ inkjet media white spectral plots.

[Chris233]

Hi Stephen,

What you are describing is the variable tension on the printer's feeding due to the roll changing weight. Along with various substrates having different compensation adjustments.

There is a way to get the registration within 1/32 from roll to roll on long prints, but it involves building an independent feed system and frame. Alternatively, you can find the % compensation needed when the roll is at 25, 50, 75%

In the printing process I work with, +/- 1/32"tolerance on prints as long as 80" are required for roll-fed inkjet.

11880 has the same phenomena, but moreso as the weight is considerably more on 60" for long prints. Machines like the S30670 don't have this problem as the feed system is updated to provide consistent tension whether empty or full roll.

[Stephen G]

Thank you Ernst and Chris

Ernst: I'll dig through the driver and see if I can find anything appropriate.

Chris: I'm probably going to have to work with the 25,50,75% compensation adjustments - and tell clients to expect a small inaccuracy.

I'm going to check this tomorrow but I'm pretty sure that everything I've printed on Epson Hot Press has come out dead accurate, even at large print sizes. For that paper I use the driver's Hot Press default settings. For the German Etching I use 'Velvet Fine Art'. Out of curiosity I'm wondering if a given set of media settings contains adjustments for handling and tension. So if I use Velvet Fine Art for a paper that is not VFA then maybe the printer won't be feeding it correctly.

[shadowblade]

So how do you deal with this problem and make sure every print comes out exactly the same size? +/- 0.3% is a fairly significant difference when you're making multiple prints that all have to be the same size.

[jimnickelson]

Stephen,

I'm having what sounds like a similar problem on an Epson 9900 and a Mac. Relatively recently, many of my prints on fine art matte papers are coming up a little bit too small for no apparent reason. I'm having the problem on cut sheet papers but not on rolls, so my issue at least is not related to roller tension, etc.

Prints I've made for years without issue that were 16" long, for example, are coming out on Velvet Fine Art paper as 15 3/8" long. I'm using the same file and settings but something has changed, and I can't determine what it might be. I can fix the problem by enlarging the images about 2% before printing, but that is obviously not a great long-term solution.

My best guess is that it is something with the Apple-Epson driver interface that changed with a new release of software. I've tried printing via Adobe products (LR and Photoshop) as well as Roy Harrington's Print-Tool and I've gotten the same result, so I don't think it is an Adobe issue if it is indeed a software issue. If that is the issue, it could be impacting you as well.

I've been using the Velvet Fine Art media setting for printing on that paper, naturally, but I will try it with a different setting to see if that helps out.

I don't know if this is the same issue that you have, and I don't actually have a solution as of yet, but it can at least hopefully give you a little more data in diagnosing your issue.

- Jim

[jferrari]

Stephen, think of it like the tires on your car. When they were new they gripped the road very well. As they aged they became worn and dirty and therefore wouldn't grip quite as well. Similar principle with the feed rollers in your printer. They are no longer new and don't grip the media as well as they used to. That is why Epson has provided an adjustment for that in the printer configuration dialog box of your printer driver. You may have to play with the settings to get it just right but it works for me to within a few thousandths.    -Jim

[hugowolf]

Except this is what Epson has to say about the Paper Feed Adjustment slider:

"Modifies the speed of the paper feeding to compensate for banding in the direction of the print head. If you are seeing 'white' banding, move the slider in the negative direction. If you are seeing 'dark' banding, move the slider in the positive direction."

Brian A

[jferrari]

Except this is what Epson has to say about the Paper Feed Adjustment slider:

"Modifies the speed of the paper feeding to compensate for banding in the direction of the print head. If you are seeing 'white' banding, move the slider in the negative direction. If you are seeing 'dark' banding, move the slider in the positive direction."

Brian A

That's just the description in the manual. If that was it's only function they would've called it the "Banding Adjustment Slider." Obviously the control adjusts the line feed distance which is a solution for the OP.

[Chris233]

Jferarri, yes and no..

You're right about the nip rollers, brand new they are tight enough you may even notice impressions or patters on the substrate emulsion. Over time, they relax and along with it, change the printed dimensions.

The feed adjustment is designed as outlined in the manual. The nature of the adjustment does change printed dimensions as a side effect. But with each change in the feed adjustment slider, does also change image quality (for better or worse)... Certainly you can dial it in within a few thousandths for a particular area of a roll. But if the roll carries any weight and substrate heavy, it won't hold that register for long. Consider also the weight of a long print falling into the basket also pulls down on the nip rollers, so that too shifts the adjustment.

You may end up chasing your tail between image quality and print dimensions if using the feed adjustment as correction for both on multiple types of papers/substrates...

Perhaps easiest to keep those adjustments separate. apply distortions to the image as needed, and keeping a spreadsheet handy for the various substrates. Each machine has a slightly different distortion and feed adjustment with the same print on same roll. It reveals itself further with longer prints and when printing single channel halftone screen gradients.

Shadowblade, it would involve building a feed system independent of the machine, and replacing the OEM frame to support it. This would be for prints 30"+ as less than ~30 the 9900's should remain within 1/16

[hugowolf]

I wish you guys would do units. Thousandths or 1/16 ths of what? mm, cm, miles, kilometres?

The printer driver does mm and inches with decimal fractions.

Brian A

[Stephen G]

Reading through everything here it seems to me that the most likely cause, in my case, is the rollers not pushing the paper through effectively enough. Either they are old and can't anymore (the printer is nearly 3 years old, regular, but mild usage) or the surface of the paper itself is causing them to lose grip. Or both.

Some thoughts and tests:
I'm only getting short prints, not long prints.
The percentage difference is the same on 40cm prints as on 130cm prints - so the weight of a hanging print seems to make no difference. I expect this would make prints longer than expected anyway.

I tested it on a cut sheet of German Etching, same print settings (VFA) as previous jobs: print was ca 0.25% LONGER than expected. 370mm sent, 370.9mm printed

I then ran the same test using Epson Cold Press as the setting in the driver, changing nothing else: print was dead accurate, as far as I can measure

Then I thought that moving the paper in smaller increments might affect things, so I tested again using the VFA settings, but changed the print quality to level 5: same as first test, longer than expected.

Clearly roll and sheet behaviour is different, so I have to test things on the roll again as this is how I do all my German Etching prints. I'm using the hahnemuehle canned profile so I have to stick with VFA, level 4 as my media setting.
Maybe the back-tension is too much, resisting the feed rollers. Can't reduce it, but can INCREASE it to see if that has an effect.
maybe the suction bed is too strong, resisting the feed rollers. Can decrease it, but risk head strikes if I reduce it too much and the paper lifts off the bed.

hmm

gotta actually do some work today, will test these next time I have a chance.

[hugowolf]

... I'm using the hahnemuehle canned profile so I have to stick with VFA, level 4 as my media setting.

No you don't. It is generally better to do that, but it isn't imperative. If another media setting gets you what you want, then go with it. I think VFA puts down more ink than other media settings, so VFA and 2880 dpi maybe too much, but a small test print should show that. 2880 dpi puts down very little more ink than 1440 dpi.

As far as I can remember, the ink loading from highest to lowest in matte paper are:

Velvet Fine Art Paper
Enhanced Matte Paper
UltraSmooth Fine Art Paper
Singleweight Matte Paper
Watercolor Paper - Radiant White
Textured Fine Art Paper
Plain paper

Brian A

[Stephen G]

Brian, I'm not worried too much about the difference in ink load between 1440 and 2880 within the VFA setting, it is a very small difference. I don't really want to run at 2880 anyway, as it's too slow for large prints. I'm worried that if I change the setting to, for example, Cold Press, to get better accuracy in dimensions, that I'll be changing the ink load dramatically enough to affect colour accuracy.

I've yet to play with the media preset adjustment controls that Ernst put me on to earlier. Found 'em, but didn't have time to change anything.

Lots to test and play with, but I'm off the desk now for 5 days so I'll have to recap and sort this out next week.

Thanks again to all for suggestions and comments.

[hugowolf]

I don’t think you will see any color inaccuracy on matte paper. I often use the color density slider ±10.

[Stephen G]

Some updates ...

I compared test prints on a roll using the VFA setting and Cold Press settings. Same everything, except the selection of Cold Press vs. Velvet Fine Art in the driver.

Colour is definitely affected: easy to see a change in midtone neutrals, skin tones and blues. makes sense: different paper, different ink 'recipe'

Length was corrected, but not corrected fully. It did change the handling of the paper, but not enough to get an accurate output length.

I'm tired of testing now so, as I thought I would be, I'm using a compensation factor in QImage to get the results.

Still haven't had a chance to test anything else mentioned here