Wow I will trawl through all this when I get home ... thanks ! I do want to print my images, mainly on A3, I have a  very nice 8 ink printer and want to get the most out of it.... would you suggest always using 300 dpi then ?  I have only seen that highlighted area once I guessed it would be for the render area but when it does not show it can still print diff to what I have on screen.