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yankleber
yankleber
Inspiring
June 14, 2018
Answered

How to hide the CMYK channels of only one layer?

  • June 14, 2018
  • 3 replies
  • 5142 views

I am preparing a book cover to be printed at a CMYK offset printer. I would like to remove the magenta, yellow and cyan from some black elements (like text and the folding marks that I am going go add manually) in order to leave only 100% of Black.

In the past I have done this by importing the whole cover without those elements into a drawing program such as Corel Draw and then adding the black elements in the program that allows me to control the amount of ink on them, and so it was just to set black to 100% and the other three colors to 0%.

How I suppose to do this in Photoshop CS6?

PS: If someone is thinking about to ask me 'why do you want to remove the other colors?' the answer is that the printing service managers where I live are always complaining that the match of the 4-color on small black texts is a pain in the neck and that the CMY colors doesn't represent an improvement on black texts anyway. And I really have to agree with them. I should also mention that I live in Brasil and here we still have a LOT of print shops running over 60 years old Heidelberg machines where you make adjustments by untightening screws, moving the plates by a tick of a millimeter using hands while you hold the breath and then finally tightening screws again.

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Correct answer D Fosse

You simply cannot have text in 4 color black, it's a registration nightmare. This is a given when you prepare documents for offset press.

Which is why Photoshop is the wrong application for this. This is what InDesign is for.

If you have to use Photoshop, target the black channel and then type. Or you can delete the content in the CMY channels afterwards. This is very simple, just target the channel and fill with white. Done.

If you create this in CMYK, you also need to be acutely aware of total area coverage (TAC). If you exceed maximum total ink, you get smearing and drying problems, and the printer will not be happy. Get the correct CMYK profile for the actual process and find out what TAC is for that specific profile.

I mention this because CMYK can be a can of worms if you don't know precisely what you're doing. By the sound of your post you may not quite be there yet. Work with your printer. Get the right profile.

And next time, do this in InDesign.

3 replies

Stephen Marsh
Community Expert
Stephen MarshCommunity Expert
Community Expert
June 14, 2018

I’d just like to add that I agree with previous comments that standard ICC profile colour conversions in InDesign will convert 0r0g0b text as four colour black… However, this is a good example of when not to use InDesign for colour conversion. I generally prefer to do no colour conversion in InDesign and do any necessary conversions in Acrobat Pro.

Acrobat Pro can convert 0r0g0b elements to 0cmy100k – including text layers from Photoshop PDF files:

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

And if you have Enfocus PitStop Pro or PitStop Server, an Enfocus Preflight can convert such content using a special ICC DeviceLink profile, that will map 0r0g0b elements to 0cmy100k.

And if you or your printer is using a specialised PDF prepress workflow software system such as Kodak Prinergy – then that too will convert 0r0g0b PDF elements to 0cmy100k.

yankleber
yankleberAuthor
Inspiring
June 15, 2018

So are you guys saying that is safer to send the file in RGB instead CMYK?

Stephen Marsh
Community Expert
Stephen MarshCommunity Expert
Community Expert
June 15, 2018

yankleber  wrote:

So are you guys saying that is safer to send the file in RGB instead CMYK?

I can’t speak for Rob, however I for one am NOT suggesting that you send out text in RGB to an unknown supplier.

Text/vectors vs. RGB images are different beasts!

I was noting that there are many ways to deal with RGB text and make it K only of CMYK, if one has the correct tools and knowledge to use them correctly. So keeping the text as RGB is just a short term means to an end, not the end in itself.

However if the printing is “digital” and not traditional separations based, then there should be no major issues with the text being RGB or four colour CMYK.

Martin_Bns
Martin_Bns
Inspiring
June 14, 2018

You can't do that. When u're in channels, you see the channels of the whole document buddy.

Cheers,
Martin

rob day
Community Expert
rob dayCommunity Expert
Community Expert
June 14, 2018

Hi Martin, I think the question is: can you set black text that will output only on the K plate with no CMY values? You can't do it in RGB or Lab mode because you would normally get a 4-color black on a color conversion, but you can set type as black only in CMYK mode.

    D Fosse
    Community Expert
    D FosseCommunity ExpertCorrect answer
    Community Expert
    June 14, 2018

    You simply cannot have text in 4 color black, it's a registration nightmare. This is a given when you prepare documents for offset press.

    Which is why Photoshop is the wrong application for this. This is what InDesign is for.

    If you have to use Photoshop, target the black channel and then type. Or you can delete the content in the CMY channels afterwards. This is very simple, just target the channel and fill with white. Done.

    If you create this in CMYK, you also need to be acutely aware of total area coverage (TAC). If you exceed maximum total ink, you get smearing and drying problems, and the printer will not be happy. Get the correct CMYK profile for the actual process and find out what TAC is for that specific profile.

    I mention this because CMYK can be a can of worms if you don't know precisely what you're doing. By the sound of your post you may not quite be there yet. Work with your printer. Get the right profile.

    And next time, do this in InDesign.

    yankleber
    yankleberAuthor
    Inspiring
    June 14, 2018

    Thank you very much for the heads up D Fosse!

    I do graphic design for offset printing since a LOT of time (almost 30 years) and I always used Corel Draw for this as I mentioned before: I just make the imagery part (along with effected text) on Photoshop and then import it into Core Draw and do the texting in it because Corel allows me to remove the CMY from black elements.

    This time I was a bit lazy and imagined that Photoshop allowed this level of control and that I only didn't know how to do that.

    Now I know that it doesn't and that I just should keep doing things the same away I have doing for decades!

    NOTE:

    Man, I really hate InDesign...

    I have used it a few times but definitively don't like it and every time I have to compose a book, booklet, magazine, anyway, any multipage document I run to the grandpa of desktop publishing: PageMaker! And I still use the version 6! I am SO used to it that it's as if it was in my veins. The only problem is that it doesn't works well on newer versions of Windows so I have to keep a virtual machine with WXP just for this. I think I am a dinosaur. LoL.

    rob day
    Community Expert
    rob dayCommunity Expert
    Community Expert
    June 14, 2018

    This time I was a bit lazy and imagined that Photoshop allowed this level of control and that I only didn't know how to do that.

    I agree with D Fosse, if you have to do a lot of this InDesign is worth learning.

    If you have to use PS as a layout app, you can set type as 0|0|0|100 CMYK as long as your document's color space is CMYK, but usually it is better to edit in RGB mode and convert to the press CMYK space, because of TAC and black generation issues. You also want to keep the text as a type vector layer so the document can be saved as a PDF, where the text doesn't get rasterized.

    If you can keep your text in a top layer, you can edit in RGB, merge the bottom layers, convert to the destination CMYK space, and edit the text layer's color to 0|0|0|100. So:

    RGB layers

    Duplicate the doc and merge the bottom layers

    Convert to CMYK, select the text and edit the text layer's fill color to 0|0|0|100:

    By default the black only text will knockout

    If you want it to overprint set the text layer to Multiply

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