How to convert CMYK files to K only (C=0 M=0 Y=0) for print, PDF and JPGE

Question

I have a Jpeg image in grayscale and I need to print it in  K only (while CMY=0) instead of CMYK. I have tried with channel mixed presets and even though the info on screen is now C=0, M=0, Y=0 and K= various values, when I send it to print. The printer still prints with all the CMYK colours so instead of a clean monochrome colour I get yellows reds and blues.
Any advice would be so much appreciated!
M

Answer 1

Hi Gustavo,
Thank you for your email. My non-human printer is a cannon CLC 5151 and the funny thing is that it does print in black sometimes.
I have a psd document with C=0 M=0 Y=0 K=various which I have created with the channel mixer presets. - I sent it to print and = 4 coloured grey result
I open an indesign document and place this very same file (plus others with the same presets with which I create my composition) - I send it to print and = black only
Then, I say great it's printing on black so now I just need to export this composition as a JPEG
So I export it and when I send to print = 4 coloured grey
The is when I realise that the C=0 M=0 Y=0 and various K pressets I originally created have been lost again on this JPEG.
I come back to indesign and export a PDF and I find that my original presets to black only are now divided into CMYK colour again.
Perhaps the channel mixer presets are only a guide and they are not preserved when I import the document anywhere else, but I wonder How come this psd document prints in 4 colured grey despite what you can see on the info?
I have tried to paste the image into the black channel of a new document but I can't save it as a JPGE nor I can place onto an indesign either because it doesn't recognize the colour mode.
I agree with you in that it's nicer to get a greyscale with 4 colour ink but only if the printer is properly calibrated and ours isn't at all. and I need to present both indesign and JPEG prints and they should be looking the same.
M
Saludos desde Londres