I am measuring the inkseparation file with a Piezography K6 inkset and it appears that shades 3 and 4 are very close when compared to the differences between the other inks in the inkset.
This is the case with every paper I have, I don't have a way of confirming this with an other printer or inkset.
Can anyone measure the L* and post the values of those shades? Or, if someone is willing to print out the inkseparation.tif file using the QTR calibration mode set to an ink limit of 100 (on matte paper) I would be happy to send a small print of mine in exchange.
Thanks,
Richard Boutwell