QTR-Quadtone RIP

I have used both PDN and QTR to calibrate digital negative. I prefer the work flow of QTR and if I have a lot of time to work on my profile it is what I would use. On the other hand, if I find myself in a situation where I need to make some good prints quickly, say with a new printer, process or workshop, I use PDN.

In my own experience in calibrating digital negatives with QTR and the Epson pigment ink sets printers (2200, 3800, 7600)I have gotten smoother results when equalizing UV blocking density of the K, C and Y inks. For example, if the QTR calibration print shows UV blocking density of log 1.2 at K = 15%, C = 15% and Y = 20% I adjust the profile with that proportion of both dark and light inks. The actual value may need to increase but smoothness seems best if the ration is kept the same. So in practice the inks might be K=9, C=9 and Y=12, so other value of equal proportion as required to produce the desired blocking density.

QTR is a powerful method of making digital negatives, but if you use it be prepared to spend a lot of time experimenting in order to get the best results. 

Sandy King