Digital BW, The Print

Scott, 

My comments are speculative to a certain extent, in part because I have not
used the combination of ink and profiles you're using.  However, I have had
similar results with some of the systems I print with. 

>... I am using a 2200, Sepia K7, QTR ...

>Here's a scan of what I am seeing http://tinyurl.com/2efpz6

> ... the thinner papers seem to 
>exhibit the splotches even more than their thicker relatives.

My overall experience is that the failure of the paper-coating to absorb the
water appears to be a major factor.  The thinner Premier Art Hot Press 205
in rolls had it bad in my 7500, which pours on quit a bit of ink.  The
thicker ones are no problem.

In matte papers, I believe the paper base helps the coating absorb the
water.  Thicker paper may help more than thinner paper.  Cotton seems to
absorb the water better than alpha cellulose.

>Up to about 25% the gradient is smooth. 
>Then the noticeable splotches come in...

>Looking at the ink curves, at ~25% the magenta shade comes in.

QTR may set the ink limit for each ink, but not coordinate it for
combinations of ink.  Someone more expert in QTR should correct me if I'm
wrong here.  However, I think one can exceed the overall ink limit with
multiple inks.  As such, where you see the problem may be where a new ink is
coming in and exceeding the overall ink limit

>This scan [above] is from innova fibaprint which really 
>showed off this problem.

I first noticed the problem most seriously with glossy papers.  They have a
barrier between the coating and paper base.  This stops the paper from
helping to absorb the water.

One of the reasons I made the UT2 mix was that my UT1 mix was overloading
glossy papers.  It didn't show up with the matte papers, but when the MIS
inks became glossy compatible and I wanted to add that to the mix, the UT1
approach became a problem.  It used too much light ink.  The UT2 inkset uses
denser inks in part to avoid the blotchiness. 

(I didn't think the K7 inks were glossy compatible.)


>...I was printing the recommended 2880 ...

That may use more ink and exacerbate the problem.

>... I could see the ink sitting on top of the thinner papers, ...

Ink overload.  You probably need profiles and use less ink, particularly
less of the very light inks.

Paul
www.PaulRoark.com