Damn Savage Why Is This Only Common...
Law2 mins ago
No best answer has yet been selected by polly1. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.Thinking about your core problem. The printer person wants to produce plates for the cyan, magenta, yellow and black printing. Merely switching mode in Photoshop may not produce the best results as there will some "out of gamut" colours. That is some colours in the original RGB image will not exist in the CMYK process.
Without loads of tryouts on the actual printing process you will not be able to match the colour gamut and produce a passable final result. Why not let the printer person do this for you. After all, his expertese will be far more than you will ever be able to produce in Photoshop in an amateur sort of way.
There is an extensive section in the Help section of Photoshop on how to produce CMYK separation prints for litho process. I am sure it not just switching modes like I suggested at first. One of the major drawbacks is that you are looking at coloured light mixing on your monitor, and a printed page gives you reflected light. One add the colours and the other subtracts them. What looks good on the screen may look awful when printed. For the home printer machines you can use preset colour profile modifiers to change things at the printer to try and match the screen.
It will be almost impossible to match YOUR screen with HIS printing process.
Sorry, we can't find any related questions. Try using the search bar at the top of the page to search for some keywords, or choose a topic and submit your own question.