You can view the .qdif or .txt files that are included with QTR or that people post online. You just need to open them with text edit, and you will be able to see the ink limits for each channel, the gray_val overlap/cross-over points, and linearization, along with toning options when using color inks. There are some other options in there too for refining and tweaking the way the .quad file is created.
I mentioned this in other places, but I started writing a new user guide that goes into more detail about the .txt ink descriptor file and how to get the most out of your profiles without too much unnecessary grief, minimize some of the confusion, and cut down on linearization errors. The more I get into it the more there seems to be, and this is turning into a full on book—along with Excel templates, customized and updated test charts and reference files that allow some automation of some of the curve creation process. I will post more as it develops, but my intention is to make it possible to get professional rip level greyscale printing from qtr and affordable tools.
Richard Boutwell