Issue with dark areas printing on canvas

[bparkin]

Hi Everyone,

I print with an Epson 9880 currently on Epson Premium Matte canvas.  I had custom ICC profiles made and soft proof my prints and get great results 99.9% of the time.  However, on the occasions where I have prints with some exceptionally dark areas.... ie. a nasty thunderstorm in the sky, the darkest areas become strange looking in some areas.  Sort of like an old solarized print only in deep blackish areas. I wish I could describe it better.  It only happens in dark nearly black areas.  When I soft proof it, I don't see anything odd happening other than the loss of contrast that is normally expected on this material.  It is so infrequent that I shoot these images that I have ignored it.  But I do a lot of printing for others and it seems everyone has been sending me images that are dark with storms, night shots of light painted buildings etc.  I have been starting to tell people that I just can not print that sort of thing.  But maybe there is a solution and you folks can point me in the right direction.

Thanks,

Brent

[Robcat]

Hi Brent,
I'm having a little trouble visualizing the ill effect you're describing. Can you send a scan or shot of an example?

In any case, maybe you could try printing a step wedge or similar image containing narrow gradients in the dark tones to see if you can better tell what's happening.
Rob P

[bparkin]

I will see if I can create a file that shows the problem.  I tried scanning it, but the scanner just saw an even black.  I'll try photographing the problem tonight when I get home and post it so you can see.

Thanks!!

Brent

[ghaynes754]

I get that occasionally and it looks 'mottled' and not at all smooth.  Usually a channel cleaning (CL1) on the black channels fixes it.  Usually a clogged nozzle.

[bill t.]

Sounds like a profile problem to me.  In areas that are out-of-gamut you're in an undefined situation that may well be represented differently on the soft proofing screen versus on the print.  Turn on the gamut warning in the View menu, see if your dark areas are indicated as out of gamut.

Also, very dark areas are the most likely to be misread in the profiling process.  If you can reproduce the problem, print a strip with your custom profiles, then with the Epson canned profiles, could be informative.

If the problem is not reproducible, then yes it's likely a clog.

[bparkin]

OK this will show some ignorance on my part with respect to servicing the printer.  I have in the 30 months that I have owned the printer, never needed to clean it once!!!!  My 4800 needs a nozzle check every week, but the 9880 has been a dream.  I do not know how to get into a service mode that would allow me to do the channel cleaning.  Could you point me in the direction I need to go to do this?

Oh and for the question about me checking the gamut before printing, I do that when soft proofing.  To not check would be like missing an important step in that process.  I see nothing out of gamut when I check.  I can tell you though that the pictures giving me grief have histograms that are piled right up in the dark end.  My own photos are seldom like that, but I do have a few when I intentionally underexpose an image.  I'm not sure how that would relate other than the image simply having more dark tones needed that it could of course screw up when printing.

It is puzzling and I have no problem doing the channel cleaning thing if someone can point me to a how to somewhere.

Thanks,

Brent

[bill t.]

As far as I know, there is no individual channel cleaning on the 9880, it's all or nothing.

Would recommend simply starting an Auto mode cleaning through the printer dialogue.  If it prints more than about 4 patches without success, turn it off for about 1/2 hour to let the solvent action happen, then try again.

If still no success, you might search around for the "wet paper towel" trick and the "Windex soaked paper towel" trick which I believe have a lot of posts on this site.  That used to save the day for me on really persistent 9880 clogs, although I'm uncertain what the consequences of doing that often might be.

Yup, a histogram piled up at the left is a sure sign of somebody who has never done their own printing!

This is a longshot...is it possible you are getting headswipes on the canvas?  Once in a while you get a roll where some areas are a lot higher than others.  It creates a kind of burnished look and if you use a magnifier you can see the flattened peaks of the canvas texture.  And of course it creates mega-clogs.  The effects on the the canvas usually disappear with coating, but a good clog can be forever.

[bparkin]

Hi Bill,

I don't think that it is a "head swipe" thing.  The effect I seem to get happens along the edges of an object as it transitions from one tone of black to another.  Think of a some puffy clouds in a dark sky.  On screen you can see a soft edge that gives a nice transition and the illusion of depth.  When this problem happens, those edges become hard and the tones on one side or the other disapear into a flat black blob that has no texture of feel to it anymore.  Like someone came along and just painted a bland black tone over all the detail..... Sorta like someone took the area and ran the Photoshop Average filter on it.

I will try to get a photographic sample up tonight if I am able.  It is driving me nuts.... or perhaps the people I print for are driving me nuts since they all seem to be showing up with dark dark images lately.  I sent someone away that showed up with a light painted white church at night.  They wanted all the star trails in their long exposure to show up on the canvas.  About 50% of the trails of course vanished!!  What's with people and dark dark images??

Thanks,

Brent

[bill t.]

What you describe really sounds like clipping from out-of-gamut or a bad profile.  My first suggestion is to process the image so the darkest tones in that area are much lighter and see what that does on a test strip.  See if you get back to continuous tones, without worrying about the proper density.  If so, then maybe do a few more tests to see how far down you can push the RGB values in that area without the problem coming back.  I'm sure you've noticed that with proper profiles it can be pretty hard get tonal variation much below RGB 20,20,20 on most media.

[davidh202]

To me what you are describing sounds alot like "posterization" in the file itself, which has nothing to do with profiles or problems with the printer.
In an effort to achieve  deeper or richer contrast you may be doing too much adjustment in curves in PP ?
 
This article may help.
http://www.cambridgeincolour.com/tutorials/posterization.htm

[louoates]

Once in a while my 9800 simply stops laying down one color or another despite passing the print head tests minutes before. I've had the heads replaced recently but I suspect the mother board is the culprit. The reason I bring that up is that you can get to a place where no amount of logical thought can find the answer in your work flow.

Inspect the print under different color temperature lights to see if that affects the way the problem appears. If you see the crappy area shift around with the light source the profile might be the reason.

Next I'd print the same image on paper and see if by changing the profile you can fix the problem. That would also remove the platen gap issue from the table. If you still get the yucky look you might try to create a solid black square with a gradient mask from 0 to full black. Print that on canvas and on paper and see if you see the mottling in the same color temperature light conditions you usually use to inspect the print. If it's the printer that could show that the problem is one of handling the heavy and varying density. With my 9800 I'd reduce the black value and reprint. My profiles always print a bit darker on canvas than what I see on my monitor.

[John Nollendorfs]

Brent:
You need to identify, if this is a profile issue, or a printer issue. First thing I would do is try and print the image on paper, using a good paper profile. If you see none of the problems. Then try printing on paper, using the canvas profile. If you see the solarization look, then I would say it's a problem with the profile you are using.

Hope that helps in diagnosing your problem.

John Nollendorfs

[Bruce Watson]

Sounds like it could be an ink loading problem. This comes about because the substrate can only take so much ink. And black in the print isn't necessarily just black ink. It can also be other colors. For example, if it's a blue-black sky, your printer could be trying to make that color with black, cyan, and magenta inks. If each runs at 100%, your total ink load could be 300%. Things like this are why the pros use RIPs, so they can use ink limits and also control to some extent how black is actually made on the print. This stuff is typically beyond the printer drivers that manufacturers supply with their printers.

Is this the case with your problem print? IDK. I'm just tossing that out there in case you want to investigate in that direction. You could always send your problem file to a master printer like Tyler Boley or John Dean and see what kind of results they can deliver. These guys have the tools and the skills -- if it can be printed, they can print it.

[bparkin]

Hi Bill,

Yes there is not a lot of doubt in my mind that the people I'm printing for are clipping their blacks badly.  But they are doing it on purpose.  There is improvement when I lighten the pictures overall.  But since they were going for dark tones in their images to begin with, I introduce a boat load of noise to the image and of course their intent has been changed.  I have tested some of these problem images on my 4800 which can do glossy and the images look good on glossy paper (as expected since it does deep blacks so much better) but of course its a different printer, profile and paper.

I have been using the profiles on this machine for some time now.  They were made for me by Cathy Stratton (Cathy's profiles) and I have found them to work beautifully.  Well they work great until these super dark images come in for printing.  When soft proofing, I don't get indications of anything being out of gamut.  If I throw a "normal" print at it they print fabulously.

I'm going to try printing some gradients to see if there is some consistent spot that things fall apart as it approaches full black.  But I was also wondering if maybe the rendering intent setting might play into this.  I won't pretend to have a super grasp on it and quite honestly don't know the ins and outs of how the different ones change things.  Are there times when switching from one to another can improve things?  Or perhaps the black point compensation check box...  That has me a little confused too.  It has been a long time since I watched my "Camera to Print" video, maybe something in there goes over that stuff...

Thanks,

Brent

[bparkin]

Hi Bruce,

Well there is part of the problem.  This issue is seldom something that occurs in my prints.  It is when I am printing something for someone else.  So throwing someone elses images to a pro and paying them doesn't really make sense for me.  Telling the folks that bring me these images to throw them at the pro's isn't a bad idea though.  I'm totally ok with that.  I don't mind help local folks out with their printing, but I really wish they would stop showing up with these crazy dark pictures.

I do see what you mean about the ink levels getting heavy.  I use an Imageprint RIP on my 4800 and certainly do prefer it to the Epson driver I use on the 9880.

Thanks,

Brent

[Light Seeker]

Hi Brent. . . .  it's Terry.

If you'd like, crop a portion of one of the trouble images and e-mail it to me. I can make a quick canvas print and if it turns out fine you'll know it's something in your printing work flow. If not, the image file itself may be the issue. I could also make a quick test profile for you to try, if the issue points to your printing work flow.

Welcome to the forum!

Terry.

[bparkin]

I have made an interesting discovery on this problem.  When I softproof, I think that for ages I have been getting lucky while making a mistake..... Unless CS5 changed how this works.  Most of my own images were proofed long ago using CS4.  Anyhow, I noticed that in the proof setup, there is a drop down box that says device to simulate.  The selection says "Stylus Pro 9880 7880.  So I thought nothing more of it.  Now those that see the probably mistake coming will likely laugh....  I never dropped the box open to see any other options since it looked ok.  However, if I do open it, my profile is available there and I can select it.  Once I do.... I can see the hideous problems that were never showing up before.  Then when I turn on the gamut warning.... Whoa, huge areas are way out.

Now, the soft proof looks way way way more like the finished print.  And after looking at the images, this way, I can't see anyway that I could ever repair these well enough to print them.  Wow.  Maybe some of you might tell me that it could be done, but in the image I am looking at right now, 80% of it is now out of gamut.  Wow again.

Wonder what to do next....
 
Brent