I don't know if this has already been asked but searching didn't show anything. I would like to print some of my photos 12x8. I haven't calibrated by monitor (21.5" iMac) do I just calibrate it with something like a spyder device or do I have to get colour profiles from the lab and do it in accordance to this. What do I need to do to make my prints the same as what I see on my monitor. Any help would be greatly appreciated.