Black appears to be screened?

[ColorMonkey]

Hi there. I posted this at EFI's forum and after 60+ views it never had any replies. There may be more details that are needed and I would be more than happy to get those for you if needed. I'm hoping someone here knows what is causing this or any printers that are familiar with the printer/rip and has been able to nail down what is causing this.

Thanks ahead of time if anybody wants to take a stab at it.

Hi there I was hoping someone would be able to help with this but first let me list a few details that will most likely be needed or requested.

Printer: Ricoh 901
Fiery: 9rel2
CWS: 5.6.0.24
Software: InDesign CS6, Photoshop 5.1, Acrobat 9 Pro, Pitstop

So the deal is trying to print 100% K fills.

This is a test I set up to mimic the situation I have found myself in with some jobs that have either come through or that we have set up in house. I created a doc in PS with a 100% K fill then saved it two different ways. One as a PDF/X 4 and one as a tiff both tagged with SWOP. Then I create a doc in InDesign and build a box on the top half with a 100% K fill underneath it some black text, then place the box I created in PS underneath that. Again save the doc as PDF/X 4 and drag to the hold.

End result is the box and type created in InDesign are solid black, dark, and using only K toner (clicks as black). However the box on the bottom appears washed and under a loop appears to have a screen say 95%+ screen.

It seems that raster objects with a 100% K fill print with a screen and vector objects/text print solid.

Before I go on I will leave it at that and see if anybody has any suggestions in resolving the screening issue I'm running into. If anybody has a 901 and running same version of rip, could you please try this test and see if you get the same results? BTW asked techs and they have no idea said it is what it is basically.

Thanks

 

[Stephen Marsh]

InDesign colour settings, colour management policies for CMYK:

Preserve numbers or preserve embedded profiles?

If preserving profiles, is your InDesign document using *exactly* the same SWOP profile as the Photoshop image?


Does your RIP have options to use different profiles or rendering intents for images vs. vectors/text?


EDIT: Have you confirmed the colour values in the exported PDF using Acrobat Pro Output Preview/Object Inspector to see if this is something that is happening when creating the PDF?



Stephen Marsh

 

[Stephen Marsh]

Attached are three similar PDF test forms.

Run all three through your RIP, are there any differences in the rendering of colours that should be the same?

Let me know how you go or if you have questions about what to look out for on the form…

It may also be a good idea to run “torture test” files from the Ghent Work Group (GWG), ECI/Altona Test Suite and from IDEAlliance to see what else may pass or fail.

EDIT:

http://www.gwg.org/download/test-suites/ghent-output-suite/
http://www.eci.org/en/downloads#altona_test_suite
http://www.idealliance.org/downloads/digital-press-certification-press-test-forms-v21


Stephen Marsh

 

[Prepper]

Not to question the obvious, but your file created in Photoshop was a CMYK file wasn't it? Not RGB?

 

[Possumgal]

In InDesign preferences, is your Appearance of Black preference set to display and output all blacks accurately? This caused me screening problems years ago in Illustrator before somebody told me about this setting. InDesign has the same setting.

 

[ColorMonkey]

Hey all appreciate the response and Stephen I will run those test sheets later today after I get through my AM push.

To answer the other to questions though, yes the PS file was built/saved as CMYK (Swop).

Indesign I have tried both settings. If set to rich black it looks how I would image the black box created in PS is dark black without a screen on the fill. "Accurate" renders the screen on output.

I will be back later to give results of the test sheets.

Thanks again all, really do appreciate the support.

 

[seratne]

This is a setting on the EFI. It's been a couple of years since I ran it, but the RIP is treating vector objects differently than raster objects when it processes them through color management. Or more accurately, it is giving special treatment to vector objects that are 100% K. I forget where the setting is to change the behavior, unfortunately.

 

[ColorMonkey]

Okay so was able to run those test sheets. All return the same results.

What I see is on the left-bottom grid the 100% K is solid fill. Looks great.

The Vector/Raster Greyscale tone 10% to 100%:
@100% K the Vector is solid the raster is screened (which supports what I have been seeing)

The Vector/Raster Gradation 10% to 100%:
@100% K both vector and raster are screened

The top of the sheet @ 100% K it is solid.

To answer the questions posted:

InD is set to "Preserve Embedded Profiles"
Yes, PS and InD both have the same SWOP callout. However, the RIP does not. The rip only has SWOP 2006 Coated 3 & 5. It is currently set to 5.

As far as the question about vector/raster handling I have is found in the Grey & Black Processing which might be what your after:

 

[seratne]

ColorMonkey, yes that's the setting. Changing that will process vector black the same way as the raster. You may need to adjust profile settings to get all 100% black to come out at 100%.

 

[ColorMonkey]

That had no affect on the files I had run earlier today that Stephen had supplied. I understand this to work like this though. If rgb or cmyk are set up as greyscale values it will print using only black toner when enabled.

 

[ColorMonkey]

-One time bump

Just seeing if anybody else has experienced this or has suggestions.

Thanks again

 

[michaelejahn]

-One time bump

Just seeing if anybody else has experienced this or has suggestions.

Thanks again

Try adding the GRACoL Profile to your RIP (?)

 

[ColorMonkey]

Hey Michael appreciate you taking a stab at this. I do have the GRACoL profile included in the rip library however we run SWoP. So not that I won't give this a shot when I get a chance but you have my attention.

Why are you suggesting this, I ask out of curiosity?

Thanks again

 

[mattbeals]

What I have found with PDF's from the Create Suite apps and various RIPs/printers is that Separation Black ends up being screen. But K of CMYK and device gray do NOT. I'd suggest using an action list in PitStop to remap separation black to device gray.

You'll want to override color management in the action list as the first item in order to turn it off.
Then you can use the remap color function to remap the color Separation Black to the device gray color space.

While you're in there remapping separation black you can also look for other black or grays that you'd like to map to device gray. Like the "Auto" color used in Office is something like 13,13,13 RGB. Looks black(ish) on screen but prints screened.

 

[ColorMonkey]

Hey Matt I appreciate the response. So I think I understand were your going with that and in fact this is a problem we come up against with plots from architects who try to create there own pdfs and allow a conversion to cmyk upon exporting. The plotters seem to not like this and in turn screen the K. The fix is similar to what you have described.

My issue is no matter what 100% K vector fill is solid, and 100% K fill raster is screened ever so slightly as I said maybe 85-95% but enough to cause a visual shift from dark sat black to what I refer to as a dull flat or dry black. So the impact images/graphic is noticeable.

I have been keeping my eye on this and have been reading every response but I beginning to think that this is the rip doing this and quite possibly out of my control. However something tells me there is something else going on.

I beg anybody that has a Ricoh 901 to please build the file as I laid out in om first post and see if you get the same results. Or designers if you have one in house build such a file and have your operator test this.

I have to admit I am surprised I seem to be the only one that has mentioned this which quite possibly could just be because this is a known issue with the rip/901 or because ppl have come to accept it, not sure.

Thanks again though and if it seems I did not understand what you were getting at I apologize but I do think I know exactly what you are pointing out.

 

[Puch]

The problem can be a color management issue, which is addressed by the RIP vendors at some level, but not with a perfectionist approach you really need.

IMHO the screening happens because the 100% K (in the selected color space – SWOP) is significantly lighter than the pure 100% K of the printing device. To reproduce that color accuretely, the RIP has to apply screening to such tones. You have your options to avoid that in the case of vector elements (pure black), but the option to do that with contone objects is missing. With a good reason, since such an option would produce artifacts in images, causing customer complaints.

What I would try is to nudge the contone elements to fill the entire L axis of the device color space, by feeding RGB or LAB data to the RIP. If the contone images' black is LAB=0,0,0 (or RGB=0,0,0), then the RIP (using a direct conversion path into the printing device's color space) has to map the 0,0,0 areas to be the darkest tone of the printer is able to reproduce, which might be a screen-less flat area.

Please try to convert some of the images in your test document to RGB or LAB, make sure that the blacks are 0,0,0 (you may need to use the Curves or Levels in Photoshop to achieve that), then save them as TIFF. Now place these images to your test layout in InDesign and export a PDF/X-4 file, making sure that every element stay in its original color space (Output panel in ID). Print that file using a direct path (without any press simulations) using Fiery.

Hope this helps.

 

[ColorMonkey]

Hey Puch really appreciate the post and I will give that a shot. I think you might be on to something and can't wait to try this.

Out of office till Thursday but I assure you I will post results as soon as I can.

Thanks again

 

[Stephen Marsh]

When testing the conversion of CMYK to RGB in Acrobat Pro, make sure that you are using the “preserve black” feature, so that CMYK Black cleanly converts to RGB Black.

Prepression: Acrobat Pro - Converting CMYK Black PDF Content to RGB


Stephen Marsh

 

[Stephen Marsh]

Two new PDF test forms attached. PDF workflow/RIP test of different “blacks” (both vector and raster, RGB, Lab, CMYK, Gray), one PDF using indexed CMYK colour and the other PDF using standard “base” CMYK.

When you have time to test, let me know what patches pass/fail and if there is any difference between the output of the two forms.


Stephen Marsh

 

[ColorMonkey]

There you are Stephan good to hear from you again. Thanks for the test pages those helped a lot.

So Puch I am having on problem doing this for test for you and that is I am not exactly sure how I print to the printer without involving the rip in some way. I cannot seem to find a way to switch Colorwise off, maybe I there is and it just has slipped my mind.

However it seems like everything I have tried if the raster black is not screened it is because it is doing a composite black of some sort which is triggering a "color click" on the printer.

I did print out the test sheets you gave me and the results where as expected and even played with the black handling and achieve a few different results but it affected the vector swatches more than anything, raster still screens.

Hmm not sure I apologize I know it must be frustrating on your end not being able to run the tests yourself.