QTR-Quadtone RIP

Hi Guys.

When I'd initially used QTR with my Epson 1400 (going back a few years), I remember being completely satisfied with the virtually continuous tone I was able to achieve. This was the case up until a few months ago, or so I recall. At some point recently — though I can't put my finger on it exactly — that beautiful tiny dithering ceased. Befuddling…

There are two example files in this folder:

https://drive.google.com/drive/folders/1a72IoIl2eibH4Vdap30wStNITe0PMZZl?usp=sharing

This example image is 4x6. The overview scan is at 300dpi. The detail is at 1440.

Both printed with the same PK ink, at the same 2800x1440 resolution. The difference is the driver:

Left — QuadtoneRIP

Right — Gutenprint Grayscale (which really does only use the black cartridge)

That diagonal moiré on the QTR image is NOT an artifact from the scan — that's how the image actually looks.

It's as if QTR is no longer able to produce a small dot on my Epson 1400, or something got corrupted.

A little more about my setup:

Mac guy with latest OS X Mojave, QTR, Gutenprint, CC Lightroom and Photoshop.

I run my printer as a 4C + 2MK setup (best of both worlds), having replaced the LC and LM cartridges with 100% Eboni black.

Normally, I use QTR to print the 2MK in the LC and LM positions (C/M/Y/PK unused).

And I use Gutenprint to print 4C (LC/LM unused). With the tiny dot size of the 1400, you'd never notice the lighter inks were gone.

For the purposes of the test images, I printed both images using only the PK ink, so we're not comparing two different inks/nozzles/etc.

No clogs, and heads aligned too. 2800 super is a tiny bit better, but still not good. Bi-directional a tiny bit better, but still not good. Things get extremely weird and non-linear when printing with adaptive hybrid.

I've done my best to isolate different variables and it appears something has changed or become corrupted in QTR. Reinstalled print drivers, still the problem exists in QTR but not Gutenprint.

Thoughts?