Thanks, Charley. I take it, then, you've been through this steep learning curve yourself? I am based in the West Midlands.

Jools High, I have looked and looked at my various picture editing programmes and nowhere can I find anything that gives an RGB/CMYK saving option.

Crowhugger, I may just have to give it to the printer and say 'convert it', though I need to know what I give them is right for converting in the first place. The printers I have spoken to have showed little interest in doing that. It seems they're not used to talking to people like me who don't do this every day. Hhhmmmppphhh.