It's gray scale mode, but CMY values comes out

[chamiriri]

Hello,

When I switch to grayscale mode in Photoshop

and preview the PDF output,

I can still see CMY values.

Is there any way to retain only the K value?

1. save gray scale pds file to pdf (also gray scale)

2.   But In PDF, I can still see CMY values.

Somebody HELP me...

[chamiriri]

It was a simple problem

Maybe I'm stupid

https://printplanet.com/threads/photoshop-grayscale-conversion-showing-up-as-cmyk-in-acrobat.16211/

[TheDigitalDog]

Gray converted to RGB/CMYK through Lab; nothing new here. The CMYK values are simply those you've setup in the Color Settings for 'defalut' CMYK (whatever profile was set there). 

It's like asking how many meters are in a mile in a country that only uses meters. It's a simple conversion based on some scale, in this case, the scale of CMYK in  your color settings. 

Grayscale document. RGB and CMYK values converted from that.