Anyone seeing display problems with link-placed grayscale images?

[Gary_Newman@adobeforums.com]

I will be surprised. I've had absolutely no problems with files saved as PDF. And if some one ever needs to, try editing one of those Print to PDF files.

[Wade_Zimmerman@adobeforums.com]

Gary either way works fine. There would be no problem you will get the same result unless you print the separations from AI to PDF.

[Ann_Shelbourne@adobeforums.com]

SavedAs PDFs didn't work -- on three different RIPs -- for Jason, but Printed to… ones did.

See:
Ann Shelbourne "AI CS PDF Broken: Fix Pleaz %D" 2/3/04 2:03pm </cgi-bin/webx?14@@.2ccfa451/43>

Anyway, I would rather play safe and shall continue to output through InDesign.

[Wade_Zimmerman@adobeforums.com]

Don't listen to her!

[Ann_Shelbourne@adobeforums.com]

<< Don't listen to her! >>

Good idea.

Printers everywhere will revel in it because it gives them a chance to tack big dollars onto your bill for fixing your files so that they print.

:~)

[Wade_Zimmerman@adobeforums.com]

The Black Pirate is really worth seeing if you ever get a chance!

[Ann_Shelbourne@adobeforums.com]

I don't think Adobe welcome the advertising of Pirates in their Forums but they do have a special email address for this purpose.
<http://www.adobe.com/aboutadobe/antipiracy/main.html>

[Wade_Zimmerman@adobeforums.com]

Well!

[Gary_Newman@adobeforums.com]

But still, in matters vegetable, animal, and mineral,
He is the very model of a modern Major-General.

[Gary_Newman@adobeforums.com]

I'm generally never one to beat a dead horse. But I find myself - one who, at the outset, admitted to not caring - revisiting this.

When an image - RGB or CMYK - is opened in Photoshop and converted to grayscale, it no longer has any colored pixels in it. Saved as EPS or PSD, it is still grayscale. If I bring this file into a CMYK illustrator document, it remains grayscale. When I save this file as AI, EPS, or PDF, it remains grayscale. Opening any file that has gone through this route - and there are a lot of vriables that can happen along the way - in Acrobat, always gives me a grayscale file.

In the days before you could save directly as a PDF, you could print the file to PosScript, and then Distill it to PDF, which could then be easily sent to a printer. Printing to PDF is just the shortcut for doing this. And a grayscale image that goes this route in Illustrator, stays grayscale.

So what's the difference? I'm sure there are a lot of technical ones that elude me, but one is that the Print to PDF file is a lot smaller, which can be nice. The Save As version has a lot more data in it. You can see this by trying to open a Print to PDF file in Illustrator. Compression makes no difference unless you have very large or high-res images and you wish to use it to make the size smaller. Using the Press option puts printers marks on the plate - and then you will get data on all four plates.

I haven't seen Ann's test file, so I don't know it's content. But I'm guessing there's no text on it. If I put black text on my file (along with my grayscale image) and Save as PDF, everything is fine, as noted above. If I print it to PDF, again, the grayscale image is fine - but now I have the text on all four plates. Not good.

By the way, I believe your computer has to be connected to a Postscript printer for any of this to work. If you just have a non-Postscript inkjet, you'll have all kinds of problems.

[Wade_Zimmerman@adobeforums.com]

Gary you don't need a postscript printer as you can Adobe PDF as the printer if you Acrobat 6.01 or Acrobat 6.01 Pro, just in case she has not there is a 6.0.1 update
but I am sure she has done so.

Also the Save to PDF uses the chosen PDF Preset as the settings I am not certain.

But the Press default placing the register marks on the four plates would probably account for Ann's findings. As Illustrators has them off does not have the when she Printed to PDF she probably had the turned off and therefore got no information except on the K channel. You have found the answer to this mystery and Ann was correct do not use the canned Press settings as your default if you are printing grayscale us the Illustrator settings as the default.

In the PDF Presets is where you change this I have and I suspect you do and that John Kallios has the Illustrator settings set as the default which is what the Save to PDF settings rely. She chose to have Press as the default so Illustrator use those settings
which as you noted has printer marks turned on.

Now we all know what to look for and tell a printer to look for when sending a file from AI or ID or PS and things are going wrong and they can easily correct the matter.

By the way the Illustrator default has ZIP compression and the Press has JPEG.

BTW Ann I the files I sent to that printer where from ID the two sent from AI where fine.

[John_Kallios@adobeforums.com]

There is no denying that there are some bugs in Illustrator's save to pdf.

But, I do not believe the symptoms that Ann experience did not have anything to do with the save as pdf feature.

The pdf files she sent to me were grayscale. Every single one previewed correctly in the K channel only in Acrobat's separation preview and they also ripped correctly to the black channel only. Whether I sent postscript from Acrobat, postscript from InDesign or processed the pdf natively on my rip. All processes yield separation to the black channel only. (the cmy channels were all blank.)

So, I think Ann needs to trouble-shoot her Acrobat for this matter because her separation preview for the same pdfs she sent me shows the image in all the channels in Acrobat. But, as she posted when placing the pdf in InDesign, that separation preview only showed the black channel. (I think she posted that) Ann is a bright so her results are NOT due to user error or misinterpretation. (at least no more so than I would experience :))

[Ann_Shelbourne@adobeforums.com]

Acrobar Pro v.6.0.1 was actually giving me readings of varying CMY&K percentages from a grayscale image when I had made the PDF by SavingAs from Illustrator. The PDFs which I made from the same Illustrator file but using the "Print to Adobe PDF" route produced K percentages only.

John Kallios confirmed that ALL of the PDF's contained only grayscales on just the black plate.

Acrobat's Separation Preview gave totally accurate readings from color patches and from registration marks in SavedAs files but was apparently producing erroneous readings from the grayscale.

I trashed Acrobats p.list prefs., (I am not sure which of the other Prefs it is safe to remove); and removed a trial version of PitStop which was in its plug-ins folder, but the Separations Preview readings remained the same.

Although this is only of academic interest to me (because I never prepare PDFs by SavingAs out of Illustrator) I remained curious as to why I got these readings.

<< THOUGHT >>
"What about Acrobat's color settings?"

They were set to Color Management OFF!
I set the settings to match my other programs and, with CM turned ON,
Acrobat's Separations Preview now gives the correct K-only percentages from the grayscale.

Mystery Solved!
(Although I find it strange that having CM=Off should only affect the readings for the black plate.)

But a big "thank you" is owed to everyone who tried to find the answer to this strange behaviour.

[Ann_Shelbourne@adobeforums.com]

<< But, as she posted when placing the pdf in InDesign, that separation preview only showed the black channel. (I think she posted that) >>

Correct! I did!

And come to think of it Acrobat's CM must have been turned "OFF" when i tested the InDesign-generated (and re-generated) files yet Acrobat produced the correct K-only percentages for those files -- as it did for one which was SavedAs from Illustrator but which contained an EPS grayscale.

[Gary_Newman@adobeforums.com]

Glad the mystery is solved. It was giving me a headache. I'm wondering if Adobe could revamp their Save to PDF feature to be something like Save for Web is in all their apps. You could turn options on and off on the fly, emulate Print-to, and get visual feedback with side-by-side comparisons, while watching the what each change does to file size.