How do you print CMYK separations in black?

[chascan42]

I have a color JPEG photograph that I separated into CMYK channels. I have an Epson Photo R2880 Printer (8 color cartridges). I am using Photoshop CC that I just installed. (2017.0.1 Release).

When I print, I select Separations in the Color Handling dropdown of the Color Management panel, with "Normal Printing".

This causes the printer to print out a page for each channel. (4 pages, as expected.)

However, each separation page has what appears to be a sepia or brown cast along with the black. What I expected was just a solid (grayscale) black image, with no color.

As an experiment, I saved the JPEG photo file as a Photoshop format file, re-ran the separations, and printed the separations from that file. I got the same color results. I also saved a single channel to a file and converted it to grayscale. When I printed it, it also had a color cast to it.

Is there some setting I am missing, or is there another issue here, of which I am unaware.

The essence of my question is how do I force Photoshop to print each separated channel in black only?

[gener7]

I would guess you could go into your printer settings and select "Black and White" to keep your color cartridges from simulating black.

I am by no means a print professional, but aren't color separations for commercial offset type presses that use separate CMYK plates for printing?

Do Epson (Inkjet printers) print nice half tone films for color separation? - Quora

"Inkjet printers are wholly unsuitable for colour-separation purposes, no matter how ‘high end’ the printer or the substrate material may be.

Take your computer files to an “output company” for the colour-sep plate output."

[chascan42]

Yes, color separations are used for commercial offset type presses.

They are also used for small manual lithography presses, which is what I have. I want to manually print color photographs I have taken, using manual color print processes.

Hence, the need to produce color separations and to burn each individual color plate.

[gener7 · Accepted solution]

In that case, set your Epson to "Black and White" and see how that works.

[chascan42]

When I first started this project, the Print Settings choice of Advance Black and White Photo was grayed out, and could not be selected. But, now seems to be available. I can't test your suggestion, because now one of the printer cartridges is out of ink, and I don't have a replacement. But, I will get one and test to see if this is really the solution.

Also, I would like to figure out what state the Print Dialog was in that caused the B&W choice to be grayed out.

But, your suggestion sounds like the solution.

[gener7]

I can't really say. There's a "Let Photoshop Manage Colors" and "Printer Manages Colors" setting on my Brother MFC 6920DW printer.

That's more of an office style printer with just the CMYK carts.

If I go to Photoshop Manages colors, I have a separation option where CMYK will print out as 4 grayscale sheets. I've never used it before, but there is no color cast.  With CMYK there is a standard profile "US web coated SWOP v2" that is set in Edit > Color Settings.

In any case, it can work normally. since I don't own this Epson model, you can check with Epson. But hopefully when the ink cart replacement get to you, you can still choose black and white.

An alternate might be to go to the Channels panel, choose and print each channel.

Gene

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[chascan42]

@gener7 :: Yes, I would have expected that making the "separations" choice would have had Photoshop just print out each page as "black only". But, I think what may be happening on the Epson is that it is "generating" the black, using some "black" algorithm, because Photoshop is still printing in "color". It has 8 color cartridges: CYMK, plus light Magenta, Light Cyan, Matte Black, and Light Light Black (gray).

And, yes, I also see the choice of the "US web coated SWOP v2" plus a host of other color profiles. I have a color profile for the Epson R2280, as well.

@Theresa J :: Yes, some further experimenting allowed me to create a set of half-tone plates from my CYMK separation pages using the Bitmap mode and Halftone screen option. Those halftone plate pages print out a Black with no color cast on my printer. 

I did that experimenting before my Light Magenta cartridge ran out, and actually, that ends up being the way that I will print out my transparency film to burn the plates I will print from on the press. That is because with the Halftone option, I won't need to burn a screen to the press plate first to simulate halftones.

With photographs or any other continuous color image, you have to break it up into dots so the ink plate will accept the ink. Otherwise, you just burn out the entire color area, and the plate won't hold the ink. So, the halftone has to be generated, either in the separation channel to start with, or by burning the grid in a separate step on the plate itself.

But, there isn't any need to convert the image file to PDF to achieve the halftone separations. That is a step that isn't necessary. However, when you convert a single color channel to Bitmap, then Photoshop is going to throw away all the other color channels. So, you end up creating four separate files: one Bitmap/Halftone page for each channel.

[Theresa J]

Chas an, I thought the bitmap option would probably work for you. I'm glad that you figured it out. I think what you and your wife are doing sounds really interesting. I spent most of my early career working in prepress. Because of that influence, I am always thinking about new and interesting ways to print my art.

[chascan42]

I have loaded a new ink cartridge and was able to carry out the experiment with setting the Color control in the Print Settings dialog to "Advanced Black & White". This setting printed each color channel separation as Black with no color cast.

So, gener7's instruction is correct.

I also figured out why the "Advanced Black & White" setting was grayed out the first time that I tried to set it. I had the media set to Plain Paper, because that was what was loaded for my initial test. You have to set the media to Ultra Matte or some other appropriate art paper in order to set the print color to black and white.

In any case, I have it sorted now. Thanks to you guys for the conversation and suggestions.

[gener7]

chascan42 wrote:

I also figured out why the "Advanced Black & White" setting was grayed out the first time that I tried to set it. I had the media set to Plain Paper, because that was what was loaded for my initial test. You have to set the media to Ultra Matte or some other appropriate art paper in order to set the print color to black and white.

In any case, I have it sorted now. Thanks to you guys for the conversation and suggestions.

I'm glad to hear it's fixed. Something about printer settings that can turn a right answer into a wrong answer. 

Gene

[chascan42]

@Theresa J :: So, if you spent time doing pre-press work, there probably aren't too many mysteries about halftones and printing technology for you.

Thank you for your kind comments.

[chascan42]

I also wanted to address the quote from gener7's original answer post.

"Inkjet printers are wholly unsuitable for colour-separation purposes, no matter how ‘high end’ the printer or the substrate material may be.

Take your computer files to an “output company” for the colour-sep plate output."

My wife has printed a number of color-separation transparencies used to burn the plates for manual printing on our press and quite successfully. These are reproductions of her hand-drawn artwork, and have worked quite well.

So, while inkjet printers may not be suitable in all instances, and for all printing applications, they definitely do suffice for certain applications. Just as with all art, you have to match your tools and processes to your intentions.

For an example of an image that was printed on our press, using four-color separations printed out on an inkjet printer, then burned to plates for final printing, see Blue Clara.

[Theresa J]

I did a quick google search and came up with this youtube video that I think does what you are asking. Basically you print to a Postscript file, convert to PDF which creates a page for each channel. Then you convert each of those to a bitmap tiff in Photoshop.

Print Color Separation Halftones WITHOUT RIP Software - YouTube