Blending Mode

ColorMonkey

Well-known member
So just recently as in the last couple of weeks we are starting to get customer supplied PDFs that do not print correctly. The only thing they all have in common is that, when viewed through Pitstop, the blending mode is Compatible. For some reason those transparencies with this blending mode do not print as intended. If this was isolated to say the RIP on the laser machine then I might suspect the software however, this is also affecting images that go to the injet as well.

I cannot supply an image for someone to look over but this has happened of several jobs from different customers supplying their own PDFs. I have searched endlessly on this and have come up with nothing conclusive to either deal with the problem or even offer advise on how to avoid the problem.

I just am not sure why all of a sudden we are seeing this.

If anyone can offer any information why this may be so I would really appreciate it.

Thank you
 

abc

Well-known member
Some questions.
What application are the files generated in?
What rips do you have?
What happens when they print, what goes wrong, is it only with Compatible blend mode or others as well?

Compatible is actually the same as Normal Blend mode, so there's actually not a lot of blending going on.
You could try changing the Compatible Blend Mode to Normal and see the result. I can send you an Action List to do that if it helps?
 

ColorMonkey

Well-known member
So this is where stuff gets a little tough. I know one job supposedly was created in InD then exported to pdf. Another was three art prints that were exported and submitted as pdfs. The inkjet printer said something is wrong it is printing out as blue and black. That's when we checked the file and noticed there was a transparency and it was set to compatible. When you open the pdf in Photoshop the image was exactly like it was printing out, black and blue (supposed to be a sepia type tone). Another I'm not sure but it is from a customer that I believe is using the Adobe suit and would of created in InD then exported and submitted a pdf. Again we only knew this was affected by something on output because it did not look like the preview in acrobat so we actually sent this back to them and asked them to set the blending mode to Multiply and it ran fine from there.

On the first job I forgot to mention it was a logo on top of a Pantone background. When printed the (raster) logo disappeared. When inspecting the image you could select the logo and it would say it was the Pantone used for the background, but it wasn't it was just a multicolor logo.

So First and Second job was inkjet using the internal rip Canon Pro6000
My Rip for the laser is Fiery E-43.

So lastly interestingly enough I took one of the three "art" files mentioned above that was outputting the sepia like image to solid black with so blue detail into my InD and just placed it and exported it to pdf. I check the transparency and it was Multiply, not compatible. Did the same thing on one of our Macs as well, same result. Any files we create in house no problem and since we can't recreate this problem we are sorta lost as to why this suddenly is an issue with file supplied.

Hope that gives a little more info abc and please ask me if you need more. I really really do appreciate you jumping in on this.
 

ColorMonkey

Well-known member
I sure will. I'll get back to you tomorrow on this as I am about to go home for the evening.

Talk to you soon
 

ColorMonkey

Well-known member
Actually we did run the script and same problem but I am going to let you have the file (granted each case may be a little different I don't know) to see what you see in this one. The thing is, we can fix the problem we just don't know why the file that are being submitted have Compatible tagged as the blending mode.
 

Attachments

abc

Well-known member
So this is the file with the disappearing logo?
It's a Spot Color set to overprint. If you convert that Spot Color to CMYK, then the overprint no longer works as you can't overprint CMYK on CMYK.
I suspect that's the issue.
 

ColorMonkey

Well-known member
Okay I'll give that a try there is one issue with changing the spots to CMYK however. On the inkjet it has no Pantone library to refer to therefore uses the alternative space if the file has a spot callout. The laser however is different and does.

The reason why this is an issue is because th alternative forulas for spots are not always translated to be the best option. So a lot of the time I need the spot callout so I can then grab it in the RIP and tweek it to get closer to the Pantone callout.

And again it can be fixed so that the file will output as intended and still allow me to grab but not when "Compatible" is assigned to the transparency.

So for the inkjet no worries but for the laser it is a different situation.

I will pass the script to our graphics person and will get back to you with some feedback.

The question still remains though on why these pdfs are coming to us this way and what the customer is doing. I assume assigning overprint but how are they doing that and why? Again just recently say the past month or so we have been getting more pdfs with this problem.

abc, thanks again for working on this with me.

BTW yes that is what is happening the logo disappears and you are left with a knockout.
 

ColorMonkey

Well-known member
Okay so here is a slice of the "art" image. If you just drop this into photoshop it turns black with blue detail. This is exactly how it print on the inkjet. Again "Compatible" assigned.
 

ColorMonkey

Well-known member
Macmann I'm sorry that was stupid of me to post that instead of PM. Can you please delete that from your post, thank you.

So I know that's what I mean I don't know what is going on but the pdf displays correctly it's just on output. We again can fix it but we are trying to figure out what it is that is causing these files to assign Compatible in the Blending mode. Very strange and I agree maybe a bug but just not 100% sure. We don't have this problem it's only showing up on files that are submitted.

I'm starting to wonder if it is a 3rd party PDF convertor they are using but one customer I am 99% sure has Adobe Acrobat. So doesn't make any sense.
 

Macmann

Well-known member
Photo has been removed-I'll leave this reply though-it may spark another idea.

It appears the color was inverted somehow, a software glitch perhaps? To confirm I opened it in Photoshop and under Image --> Adjustments --> Invert. We used to scan old film negatives and just invert in Photoshop. I hope this leads you to a solution.
 

abc

Well-known member
That PDF of the whale seems to be a perfectly normal file with a Device CMYK Image that has Jpeg encoding and a resolution of 300 dpi.
PDF Producer is 'Adobe Acrobat 19.8 Image Conversion Plugin'
If I open the PDF in the latest Acrobat (which doesn't prove much honestly) it opens as I see it in Acrobat.

To be honest from a PDF point of view I can't see anything here that would cause this to output any differently.

How are you printing this to the rip, as a PDF or some other way. Personally I think the best way to handle it is to log a call with your rip vendor, they will be able to diagnose and see if it's a file or configuration issue.
 

ColorMonkey

Well-known member
So this paticular image the guy running the inkjet after talking to him a little more diid not send this as a pdf. I guess he needed to make adj to the image so he opened it in PS (this he did not explain initially). So I guess when he did that it displayed black and blue and he then printed a proof to see if this was how it would print, I guess confused that the pdf looked okay, and got what Photoshop displayed, black. He then said he sent it through acrobat and it printed fine.

The third image I mentioned is something I cannot send but was sent to the laser RIP and this is done simply by dropping the pdf to the hold and going from there. The deal with this image was it just was not printing as intended but when we sent it back to the customer and asked to change the blend mode to Multiply as I mentioned before, it printed normally.

I don't want to go down a rabbit hole with this but it is interesting that the problems we are running into seem to be with this blending mode. Again once switch in Pitstop to normal or multiply respectively, we can rid of the issue.

I will go ahead and for now see if we run into more issues with this and if I do I will go ahead and try to post the file with an explanation of the problem.

One question though abc, we cannot generate a file that has a Compatible blending mode no matter what we have tried. Is this something generated from using an old version or Acrobat and/or a 3rd party convertor or why are we all of sudden seeing this come from some customer files?

Thanks again very much!
 

abc

Well-known member
Ok well that was fun.

You piqued my interest as I really had no idea what was going on, but there were a few clues.

So attached you have a simple Indesign 2019 file with 3 overprinting objects, overprint is a trigger for Compatible mode from what I've read.

Then from the Indesign you have an exported PDF/X-4, an exported PDF/X-1a, and a generated PS file and associated PDF generated with Distiller (and that's the first time I think I have used Distiller in about ten years!).

Result: PDF/X1a - Normal Blend Mode. PDF/X-4 - Normal Blend Mode. Distilled PDF from Postscript - Compatible Blend Mode.

That fits the binder you sent me which was also created by Distiller.

This from an Adobe Tech Note on transparency from 2000.
There is a special blend mode named Compatible, which is the default value of the blend mode parameter. This blend mode implements overprinting and erasing behavior that is compatible with the existing Adobe imaging model and PDF 1.3 when painting opaque objects. To do this, it consults the current values of the overprint flag (set by op or OP in a graphics state parameter dictionary) and nonzero overprint mode (set by OPM), as follows: ...

Things have moved on a bit since then, so my assumption is by going back to the last century and exporting postscript, the Compatible mode is generated when distilling.

Having said that, this should not be a problem for your Rip. But at least you can fix it.
You can create a preflight for Distiller as the PDF Producer, or for the existence of a Compatible blend mode, or you could just fix it with an Action List.

Have a good weekend!! :)
 

Attachments

ColorMonkey

Well-known member
Okay good info and I did read that tech note but it especially said this should cause no issue which left me confused. Apparently it does effect objects when ripped though or at least on the Canon and our Fiery RIP.

Last question and going back to the file I first sent you. How would one assign as it seems they did a raster object to overprint. I know with vector you can but how would they have built that to assign it to the rastre logo?

Alright abc you have a good weekend as well and appreciate all the help. If you get a chance to respond to my comment above that would be great to try to understand how these customers are building their files.

Take care

BTW I am going to print the three pdfs out and see if they all work.
 

abc

Well-known member
Setting the image with a multiply transparent blend mode is probably the best option.
 

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