SHort asnwer:
Image -> colour mode -> Lab
Image -> colour mode -> CMYK
Or simply:
Image -> colour mode -> CMYK (since PS will referenc ethe Lab colours anyways)
Long answer:
What are you trying to do exactly and where does the problem come up?
Hi,
I am creating a poster that will be printed on offset. It contains the picture of a sunset that fills the page. The colours are strong. I figured I must do something with the Lightness channel in Lab mode before I save to CMYK, for best results.
I’ll take the long answer.
Thanks,
K
Whenever you do a conversion from one mode to another, Photoshop already converts and references the conversion using Lab.
So if you do a simple RGB>CMYK conversion, it’s really doing a RGB>Lab>CMYK conversion.
The colours are strong.
then you may experience some desaturation when converting to CMYK, this is normal and reflects the limitations of CMYK inks. You may want to do some (minor) adjustments to the colours after the conversion to CMYK
