QTR-Quadtone RIP

I am setting up a 3880 with Eboni-6. I use 8 positions of Eboni ink -- one MK and 7 dilute positions. Some of the profiling approaches I use may have application to other similar inksets.

With many dilute carbon inks, I prefer to have at least 2 "channels" or "partitions" running at the same time. So, my "default" approach is the have a main "gray" partition using standard QTR semi-automatic partitioning. I then set up the LLK and LK, which in the Eb6 inkset I have duplicate the LC and C dilutions. (C is 30% MK; LC is 30% C [9% MK]). I can also increase the channels to 3 by splitting the main Gray partition into 2.

More overlaps can accomplish several goals. It hides the cross-overs and has more inks firing at any one point. This absorbs/hides paper and ink batch differences better, and also hides microbanding better.

Take a look at pages 7 & 8 of http://www.paulroark.com/BW-Info/3880-Eboni-6.pdf to see what these types of profiles look like. Note that in these samples the basic dilute ink limit was 50. When more than one partition or channel is going to carry the load, that ink limit needs to be manually split between (or among) the "Gray" and "Toner" partition(s).

With some profiling approaches I've seen with some other high-K position B&W inksets, it appears to me the ink loads get very high. I've observed bleed in print samples that is consistent with that. Mottling is often another symptom of an excessive ink load on the paper. I tend to have the ink limits for even the dilute inks at where the MK tops out. The denser inks clog the pores of the paper first. For simplicity I often just select that MK dmax point for the ink limit of the more dilute inks, even though they can be pushed up higher.

(On the samples shown, which were for Arches, an un-coated watercolor paper, I accepted more bleed in the K position because the paper does not have a coating to get overloaded, and I can achieve a higher dmax with higher ink loads *on that paper.* So for the ink limit approach, that sample shown is not representative of a coated paper.)

FWIW,

Paul

PaulRoark.com -- Paul Roark's Photographic Home

So, out of all the folks who say they don't see microbanding on these
printers, are any of them using black-only workflow (single ink)? That is
where the 1400/1430 has difficulty, and especially the 1430, where I have
to lose at least a full inch on the leading and trailing edge using a
single ink to eliminate the microbanding. On the 1400, I could get away
with 1/2".

Andrew
http://andrewsharpe.com

On Wed, June 3, 2015 5:03 pm, sanking@... [QuadtoneRIP] wrote:
> I have never seen micro-banding at the top and bottom of the page with
> QTR and either the Epson 3800 or 3880, or with any of the wide format
> professional models. I definitely get it with QTR and the Epson R3000,
> and see it in a friend's work with the Epson Artisan 1400. I do not get
> the micro-banding with the Epson driver and the R3000.
>
> Sandy

It also begs the question that, if the mechanism for printing at the
leading and trailing edges are handled by QTR for the lower end printers,
then why, when printing with the same profiles and the same QTR, would the
banding be worse on a 1430 than a 1400, both at the highest resolution
(2880/unidirectional)?

Andrew

On Thu, June 4, 2015 1:16 am, brian_downunda@... [QuadtoneRIP] wrote:
> I thought that this brief post by Roy dealt with the issue of the
> microbanding rather succinctly:
> https://groups.yahoo.com/neo/groups/QuadtoneRIP/conversations/messages/12
> 758
> https://groups.yahoo.com/neo/groups/QuadtoneRIP/conversations/messages/12
> 758
> Give this, I'd very surprised if the R2880 didn't suffer from it.