Sorry Blowhard I didn't realise you had already gone in deep and sorted your systems colour management and presumed this may be the prob with the lightening colour's. I just recall when I was at a design firm they had to go thru the process of fully calibrating all the monitor's, scanners, Lrg format printers with all the different printing firms that they used. Sticking an electronic eye to the monitor's and testing them and just remember it being a right pain in the ass for them with a lot of tweaking. I suppose having your own Lrg format printer and keeping it all in house is a result because you can see the results of any tweaks straight away. Do you print all of your own profiles for clients on your Lrg format? Just out of interest how much approx does it cost you for say an A1 print (aircraft in middle, bit of writing and rest white space) including ink usage and paper (not artworking costs?) PM if you want dude?
Thanks
Clint