QTR + MIS Carbon inks: Banding-Free Gradients ?

[Ken Lee]

I've been trying to print some photos which contain large smooth gradients in out-of-focus areas.

Using the available QTR tools to make profiles (including linearizing tools provided by Richard Boutwell) I have been unable to make prints whose gradients are truly smooth. The banding is not blatant, but present enough to spoil the image, especially on large prints.

I suspect this is because measuring only 21 steps is an inadequate approach. Also, my consumer-grade Spyder spectrophotometer gives me imprecise and varying readings: I have to average them out.

Prints of ordinary subjects look perfect. This problem only appears in images which contain substantial gradients. This isn't about print head alignment or cleaning cycles, this is about the quality of the profile.

Somewhere I read that Piezography profiles are custom-linearized to exceed the imprecision inherent with ordinary QTR tools. This might explain why they are available for only a limited selection of papers.

Has anyone printed out any gradients using Piezography inks ? Is there banding ? I mean, any banding at all ?

Better still, are there other ways to get a truly linearized profile ? I mean... linear.

Here's a 16-bit Grayscale TIFF file which reveals banding when present: http://www.kennethleegallery.com/ima...BullsEye51.tif. It combines both a continuous gradient and 51-step wedge as a Bull's eye.