Grayscale image is true black, but prints in color?

I have a CMYK file with grayscale images - if I check color seps in Acrobat, it shows these images as being ONLY on the black plate - nothing in CMY. They look grayscale on my HP desk printer, but when sent through the RIP on the Canon 7000VP, they print with a definite magenta hue. What's going on?

 

Hi Tattoued,

Could be some color settings on your RIP. When you send it to the RIP, how are you sending it? Printing? Hot folder?

If printing, check to see if there is a grayscale or monochromatic setting within the printer driver.
If sending through hotfolder, you may need to configure another workflow path for grayscale only work which would generate only a K separation.

Regards,
Greg