Probably a simple question this time. I have this PDF made from MS Word here and all black text shows up as "Gray"-colorspace in both the separations preview as well as the Pitstop Inspector. In the separations preview in Acrobat it shows up as 100% K, in Pitstop as 0% "Gray Color".
If I use Pitstop to convert it to CMYK it becomes 78/68/58/94, but isn't gray just the black channel of CMYK...? Well, now here is my question: Is it still necessary to remap this 0% gray to CMYK (100% K) in that case?
Looking forward to your answers, maybe somebody can bring light to my dark (I know I have a lack of knowledge...) :drunk3: :shoots_self:
Use the Acrobat Pro Output Preview Object Inspector to click on the text for another opinion!
I would have thought that the text would be 0rgb, however the PDF conversion routine may have done something about that (my MS Word generated PDF files are RGB).
Acrobat Pro can convert maintain solids in various conversions:
http://prepression.blogspot.com.au/2014/06/acrobat-pro-convert-rgb-black-to-cmyk.html
It is all about using the "Convert Options - Maintain Black" option.
With PitStop Pro, use the map command to simply "transfer" the solid gray to 0cmy100k.
Mapping is usually used to maintain values, while conversion may maintain the look but not the values.
In the separations preview, if I choose RGB, the black text disappears. If I choose gray, the black text appears and the colored stuff below disappears. Oh, and there are some black rectangles, they behave the same like the text.
Here's a link to the file, you can take a look at it yourself, maybe my Acrobat is somehow broken... So here it is:
https://drive.google.com/file/d/0B4vV6_zsh9xXTWRMUXBLU3NveXM/view?usp=sharing (https://drive.google.com/file/d/0B4vV6_zsh9xXTWRMUXBLU3NveXM/view?usp=sharing)
But my question is, if it is really gray, would it still make sense to remap to 100K? If I reduce the file to its black content only and send it to our C7000, it shows up as black and white in the RIP. But how about offset workflows? Would it RIP black only or become 4C-black? Or anything else?
Edit: I'm on Acrobat 8, by the way, with limited color conversion options...
Acrobat Pro 8 still has the "preserve black option", however it is missing the object inspector that was introduced in v9.
You are right, in theory - solid gray or 0cmy100k is both the same thing if going to separations on a traditional press... However for the components of a PDF file and possibly a RIP/DFE for a digital print process, there could be a critical difference if there are different profiles for each colour space (more so for tones than solids).
You can leave device gray alone in most circumstances. Otherwise remap color device gray to black. Do NOT convert with PitStop-
OK guys, thanks for the responses. I've just been confused about it and wanted to make sure it really rips as black and does not suddenly become something funky... Since it seems to do so, I'll just leave it untouched.
It depends on what the RIP does with device gray. Typically for b&w digital printing device gray is exactly what you want. On some digital color machines you want K of CMYK. But some machines used to count K as a color click versus device gray as a black click. Others would count any K only (device gray too) page of a larger job as a color click because the job contained color. Mind you, i'm sure that how the color machines handle device gray may (likely) has changed. Device gray cannot overprint, so if it's part of a job where overprints are necessary then you want to use black or separation black. But if you use separation black on b&w digital machines it may come out screened. Some RIP's treat device gray as device gray, some treat it as K so overprints can be forced.
When I sent work to B&W digital presses I always used device gray so I could be absolutely certain I was getting the tone values I wanted. When I was sending jobs to color devices I always remapped device gray to K or separation black.
He went thru some various ways to convert Blacks in yesterdays Pitstop webinar
https://enfocus.webex.com/enfocus/lsr.php?RCID=5c57638d29eb41fcf1009fad1d9d1ae0 (https://enfocus.webex.com/enfocus/lsr.php?RCID=5c57638d29eb41fcf1009fad1d9d1ae0)
Even if you do fuck it up, with PitStop it's a simple step to grab the offensive color and remap the document to 100% K.
Our color printer seems to handle black and gray equally, it doesn't matter if I drop the file as 100K or as 0% gray, it'll always count as a B/W click. That's good. And if I have to send out one of those files to an offset print shop in the future, I'll remap to 100K first. This should avoid misunderstandings from their side, too. :banana:
Wait, you actually check files you send out to make sure they are correct? You do things different (right) over there in Taiwan.
I constantly get files from a printshop with a "prepress" department with totally wrong specs. Wrong spine size, 1c jobs having 4c+spots, layout all wrong, spread sizes wrong. The sad part about this is they actually set up the spread files. One thinks he's the best prepresser in existence but doesn't know what ink manager is. He the same one that argues with me about trap, he doesn't know where overprint preview is in acrobat.
Actually checking the files is just self-protection. Because once I send the file over there, it's like pushing the "Print"-Button on our own machine. I guess eight out of ten prepress people in that place will print the files unseen, unless maybe you give them an Illustrator file, coz that's all they know how to handle. Shit in - Shit out. The worst thing is, that you can ask five people from there about how they want the files to be set up or what kind of equipment they use, and you'll get five different answers. Since I've made some bad experiences with that place before, I try to make everything as easy and clear as possible for them.
Luckily I don't have to deal with people like your "prepress specialist" - at least not yet. I guess that earlier or later one of that kind will appear. So far, the clueless people around me are mostly designers who think that a university degree magically fills them up with knowledge.
Oh, you deal with the same mentality, just not the exact same circumstances.
I got a file this weekend from my "expert" wants me to preflight a job with absolutely no information besides files. No flat size, finish size, binding type or run length. He's also asking how well we can match a spot color and the file is 4c so I really don't know exactly where the spot color is.
Mondays are always fun.
Probably he has forgotten himself where he has put the spot color. Now he wants you to do the preflight, find the spot color and also tell him, which color he has used. Business as usual.
No, he named the PMS color so I know what it should look like. It's likely he doesn't know where it is either and is just trying to back us into a corner in case we don't match exactly.
Quote from: Farabomb on March 09, 2015, 08:58:09 AMNo, he named the PMS color so I know what it should look like. It's likely he doesn't know where it is either and is just trying to back us into a corner in case we don't match exactly.
Use an action list to put those objects onto a separate layer. Use that to show him.
That is a damn good idea. We have convinced them that it needs to be a PMS, the 4c ends up being one of those that does not match well. The PMS is 662 and should be a dark blue and the 4c match ends up more of a purple.
I'm still going to try that just so I can lean how to do it.
if you want a lesson, let me know.
Much easier with 12 update 3 as we added a load of stuff related to working with layers!
Figures, I have a file in now that layers might help but I haven't had a chance to read up or try anything.
Platemaker is down, swamped, pressmen are having issues with the new plates, the AGFA tech is late and all the jobs today are rush jobs.
I hate printing.
So it is just a normal day in prepress?
:strangle:
abby normal
Worse than normal, nothing at all is going right.
Quote from: Farabomb on March 11, 2015, 09:43:19 AMFigures, I have a file in now that layers might help but I haven't had a chance to read up or try anything.
to avoid confusion layers in Acrobat are not like layers in other Adobe applications. I wish they hadn't called them that.
Officially they are 'Optional Content Groups' or 'OCGs"
I've been playing now for a while with this black/gray. Remapping works fine. For the RGB blacks I'll go with a combination of "Clean up RGB black" and remap afterwards. But if I set it to overprint, it still shows up as a knockout after the change. Feels like during the output to PDF, Word just gives the element below the text a new shape just around the text (actually I didn't, it just feels like). I've ran the original "Improve my office document" Quick Run from Enfocus and I get the same result. Is there any way to fill up the white areas? Otherwise I can skip this step to set the black text to overprint.
Device gray cannot overprint. K of cmyk can, separation black can. But not device gray.
I've remapped it to100%K but it still doesn't overprint.
Is it set to Illustrator Overprint Mode 0 or 1 (OPM=0)?
How are you determining that the object is not overprinting out and is knocking out?
Do you have a sample file for inspection?
OPM = 0. I check the separations preview, and if I uncheck black, you can see the black text disappear and where it was before, afterwards it's white.
Sample files are here:
Before: https://drive.google.com/file/d/0B4vV6_zsh9xXem9NdWNQZlhUZ00/view?usp=sharing (https://drive.google.com/file/d/0B4vV6_zsh9xXem9NdWNQZlhUZ00/view?usp=sharing)
After: https://drive.google.com/file/d/0B4vV6_zsh9xXMFZiUmpwUWpzNkU/view?usp=sharing (https://drive.google.com/file/d/0B4vV6_zsh9xXMFZiUmpwUWpzNkU/view?usp=sharing)
Run this global change to get the black to overprint.
[attachimg=1]
Works like a charm!! Thank you, Joe!!! :hello:
Made in Taiwan, I note the following from your two files:
BEFORE: Acrobat Pro Object Inspector reports overprint = False, PitStop reports overprint = False
AFTER: Acrobat Pro Object Inspector reports overprint = True & OPM1, PitStop reports overprint = True & OPM1
EDIT: As Matt said, overprint on gray does not work, gray must be converted to separation black or to 0cmy?k for overprinting to work correctly.
Even the Acrobat Pro colour conversion tool has the option to "promote gray to CMYK" and to preserve black.
For an overprinting object: OPM0 shows a knockout, while OPM1 shows an overprint – which makes turning off the black separation in the output preview inconsistent and confusing as the overprint flag is true in both cases.
After some more tests:
If the overprinting black content is set to "separation: black (process colour)" – then it does not matter if the objects are set to OPM0 or OPM1, they consistently overprint.
If the overprinting black content is set to "CMYK" – then the only way for the overprint to be recognised appears to be to use OPM1.
So my conclusion is to always use OPM1, whether or not one is using separation black or CMYK objects, and to play it really safe, black only objects can also be set to separation black as extra insurance.
Why overprint for device gray objects dont work propertly?? It is a separation as any spot. I understand that spot has alternate CMYK representation but essentially device gray is K separation....
It's Gray, in a Grayscale workflow (that it is designed for) what can it overprint?
I guess you would need to read the PDF specification to find out the technical reasons
I understand that single-channel-color-space doesnt need overprint but I mean an object. I could have a pdf...there are used any color spaces you can imagine (CMYK, RGB, spot, GS, LAB and so on).....output should be offset CMYK+1spot....... one GS object and one spot object have overprint.... I am looking for differencies..... two one-channel spaces GS and spot color, for one is overprint reasonable and for the second it is not.....
You can't overprint CMYK either. so if you have a spot color with overprint and convert it to CMYK, overprint doesn't work
There's a trick to set it to overprint 'multiply' with an Action List or you can covnert to Device N.
This kind of stuff is tricky indeed, thank god for overprint preview.
Yes thank god for it.
God now needs to tell designers about the function.