I'm trying to convert my photographs to cmyk so they can be printed. There are far too many colour profiles and I don't know which one to use.
Can commerical printers handle any cmyk profile or does it have to be specific to the printer?

Can someone also explain the terminology. For example, relative, absolute, saturation, undefined?
Whats the different?

Theres also an option to choose between grey iso and black and white. What does this do?

The printers I have spoken to have been super unhelpful regarding this and can't seem to offer advice regardless of the question the only response I get is "Pwinter no pwinty rgb must be cmyk only"