The two can not be compared. QTR is another driver/RIP and should be compared to the Epson driver. Qimage can not influence the black generation (substitution of CMY composite grey mixes with MK, PK + LK + LLK) in the Epson driver it has to work with. What would be nice is QTR being reshaped to a Windows driver and then QTR could replace the normal Epson driver and used to gether with Qimage. I have uttered that request more often in the Quadtone forum.

Some printer drivers like the ones for the HP Z models have a total black generation of CMY composite grey mixes, so no color ink is used when RGB is neutral R=G=B or a greyscale file is used, both in Color and in B&W mode. The MK, PK, Grey, Light Grey inks are already made neutral so no extra color inks are needed in the print to create neutrality. A bit simplified; it also depends on profiling taking into account paper white or not. Qimage can work with the HP Z printers.

With a custom B&W inkset in a 4 or 6 ink printer and custom B&W profiles based on Photoshop RGB partitioning curves a normal Epson/HP/Canon driver + Qimage can achieve what you want. I have  a 4 ink HP running like that. Can not print color with that one though.

The best you can do is create a custom profile that is already slightly warm so the slightly warm Epson monochrome inks fit best and keep that printer calibrated/profiled in time. You may need a profile editor for that or use the advanced B&W settings to add some warmth to a normal profiled workflow. That said any B&W workflow with some color inks in the mix tends to be less stable. What you also might see is bronzing, an issue that can not be solved with changing ink color mixes. Better ink compatible papers can reduce that effect, gloss enhancers or varnishes are less effective then.

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Met vriendelijke groet, Ernst

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April 2014, 600+ inkjet media white spectral plots.