Roger, isn't this similar to what we discussed in: //www.freelists.org/post/argyllcms/Creating-process-calibration-curves-Was-Conversion-omittinglocking-device-colorant Or, do you have another usage in mind? Martin Weberg 2009/6/19 Roger <graxx@xxxxxxxxxxxx>: > Graeme, > > Thank's for your reply. I managed to achieve the kinds of "linearization" > results I was after, in Excel today, through non-linear regression. But it > opened up another can of worms :(