Process black to greyscale pdf

[effigy4130]

I've got a couple of ads that I need to convert from process black to greyscale in pdf format. I've tried changing them to greyscale in Photoshop ... that didn't work, the parts of the ad (just the images, the text is all 100% black) that were process are still process. Then I tried bringing the ad into Illustrator and changing it using the Edit Colors option, and aside from the missing font problems I encountered, all the middle tones in the images dropped out and they became very contrasty.

Does anyone know of any fancy trickery to convert process grey pdfs to greyscale?

[tZ]

dump all the channels beside for the black one?- just a guess.

[effigy4130]

The grey channel is the only one that's there in the channels pallette. When the image is in Photoshop, it seems fine. It's when I save it as a pdf and then check the output preview in Acrobat that it shows the process grey.

[tZ]

Oh… I can't exactly explain what you need to do step by step but, you need to change the pdf to export only the black channel. I think The menus first option is composite that you need to amend. Then you go to separations and choose only the black… I think.

[urstwile]

I'm confused. Are you saying that the black in the PDF is more than one color besides black? Process black and greyscale black are the same thing. Where you need to worry is if other colors besides black (like C, M and Y) are being thrown into the mix.

What program are you using to create the PDF?

[effigy4130]

Yes, the grey images in the ad contain CMY, as well as K. What is it called when the ad only uses the black plate?

[urstwile]

Greyscale is correct, I just wasn't 100% clear on what was going on.

What program are you using to output the PDF?

[effigy4130]

I got the ad from the client as a pdf, I believe they made it in Illustrator, as some of the fonts were outlined. Because not all of the fonts were outlined, and one was missing, I brought the ad into Photoshop and changed the mode to greyscale.

Ultimately, the ad will print on a black and white page, so it really shouldn't matter. The printer will convert the entire page to only one plate automatically when it rips the pdf, but it's really not the appropriate way to handle the conversion.

[urstwile]

I'm not sure that it was wise to bring it into Photoshop, as that's not the best program for layout work. What if you open it up in Illustrator instead?

[sierng]

Strange. Usually when I convert to greyscale and export as pdf, I only get K plates. The only time when i got C, M , & Y added to the mix, was when i didn't flatten the image.
Maybe try what urstwille suggested, convert in illy first?

[effigy4130]

There were two problems with opening the ad in Illustrator. The first being that not all the fonts were outlined/embedded, so some of them dropped out. The second being the Edit - Edit Colors - Convert to Greyscale dropped out all the middle tones in the image and made it terrible-looking and over contrased.

[Broacher]

Yurk. Going into Pshop will make it awful if the ad is newsprint bound. Small type especially.

I use a third party plugin called 'Quite A Box of Tricks' from quite.com in Acrobat 6 that allows me to convert any PDF to greyscale in a couple of clicks.

I'm not sure if the newer versions of Acrobat do this on their own now or not, but here's a couple other workarounds:

- SaveAs from Acrobat to a PS file using Settings/Output/Color/Composite Gray as the colorspace. Then redistill the file.

- Place file into ID, use InkManager to map the Spot Black to process black and Export to a new PDF.

-Or, also after placement in ID, change the placed PDF's opoacity to 99.99%.
Use the Grayscale Composite option in the PDF export and since you've made the PDF transparent, it gets processed-- and rounded off to 100% opaque (otherwise, the colour won't change at all).

[Alan G]

If you have Acrobat, you can use Advanced>Print Production>Convert Colors and convert the color profile to Dot Gain 15% (or whatever is appropriate). You will then have only a black plate.

I've had to do this often enough in magazine layouts when advertisers sent in "greyscale" PDFs that were actually stealth CMYK.

[Broacher]

If you have Acrobat, you can use Advanced>Print Production>Convert Colors and convert the color profile to Dot Gain 15% (or whatever is appropriate). You will then have only a black plate.

Alan, I think that was added in v7, right? (I'm still in v6)

[Alan G]

You could be right. I get vague on when these things came in. There should have been a way to do that in earlier versions, though. Don't recall it either way. (It's a senior thing...;))