Lightroom cloud cannot export to anything but sRGB jpeg. You need Lightroom Classic to export to anything else. Classic cannot export to CMYK color spaces though. You would need to do that in Photoshop if you actually really need it. You generally do not want to do that if you do not know extremely well what you are doing. It is generally best to deliver files in standard color spaces. AdobeRGB is generally fine for offset output and in most cases sRGB will work more than good enough.
Lastly, you absolutely never ever want to use monitor color space. That is only specific to your own monitor and basically guarantees inaccurate color.
Thanks for that info.I have a magazine printer who says he needs CMYK, so I'll have to contact him to clarify that.Gene Gustafson Sent from my T-Mobile 4G LTE Device
If he really wants CMYK, you need to ask the question which version? US Web Coated? Uncoated, etc. There are many different versions of CMYK and if you don't do this right and geared towards their actual process you will get bad results. That is even apart from the question of black ink density and such. CMYK is a real hornet's nest and if you don't control the press something you don't want to mess with too much. Much safer to send standard adobeRGB or sRGB files and have them do the conversion in a way they get consistent results.
Thanks, very helpful! Gene Gustafson Sent from my T-Mobile 4G LTE Device
It depends whether the Printer/PrePress company prefer an Early Binding or Late Binding Workflow.
I've always worked in a company that is Early Binding, meaning that we prefer to be supplied with CMYK files. The advantages here are that the photographer/graphic designer is happy with the RGB to CMYK conversion and there is normally a better chance of colour consistency. It helps if the photographer/graphic designer knows the output (printing) profile but if not, a CMYK to CMYK conversion would normally take place with minimum difference in colour shift.
Some companies prefer Late Binding which normally means that files stay as RGB until the final conversion at either RIP stage or at PDF creation at export from a page layout application (Indesign, Quark etc.). This allows for greater flexibility for output devices like print or web, although one of the downsides is that the photographer/graphic designer may not see the conversion to CMYK until it is printed. Depending on the subject, there could be out of gamut colours which cannot be replicated with CMYK and thus, can lead to unhappy customers, as the printed matter does not match what was viewed on a monitor.