QTR-Quadtone RIP

I am making a profile for Epson Velvet Fine Art on Epson 2200.  
Percent ink, L* values for black ink of the calibration target:

0,98.7
5,74
10,59.3
15,48.7
20,38.3
25,33.2
30,29.4
35,27.6
40,25.3
45,23.3
50,21.6
55,20.5
60,19.6
65,18.3
70,17.7
75,17.1
80,16.7
85,16.3
90,15.8
95,15.4
100,15.4

Question:  where would you put the ink limit based on these data, and why?

Thanks.

--John

John

I made a cool and a warm curve for UC and VFA. I decided to set the K limit
to 75% and the Black boost to 95%, which is where the density really
flattened out in the inkseparation. The net effect was that the K went to
95% for the deepest shadows. Using Black Boost causes the K to ramp up at
the end of the curve more steeply than it would if I had simply set the K
limit to 95%. That meant that the curve would be closer to the desired form
prior to linearization. In general, I also use the shadow, highlight and
gamma values to bring the curves closer to "ideal" prior to linearization.

I was not happy with the curves and stopped working on them. In the end I
decided that the 95% Black Boost is too high because I was getting ink
spattering near the edges of the blacks. I started using the UT7 inks and
never went back to fix the UC curves.

Tom Moore

> -----Original Message-----
> From: QuadtoneRIP@yahoogroups.com [mailto:QuadtoneRIP@yahoogroups.com] On
> Behalf Of John Hollenberg
> Sent: Saturday, October 22, 2005 12:38 AM
> To: QuadtoneRIP@yahoogroups.com
> Subject: [QuadtoneRIP] Where to Set Ink Limit?
> 
> I am making a profile for Epson Velvet Fine Art on Epson 2200.
> Percent ink, L* values for black ink of the calibration target:
> 
> 0,98.7
> 5,74
> 10,59.3
> 15,48.7
> 20,38.3
> 25,33.2
> 30,29.4
> 35,27.6
> 40,25.3
> 45,23.3
> 50,21.6
> 55,20.5
> 60,19.6
> 65,18.3
> 70,17.7
> 75,17.1
> 80,16.7
> 85,16.3
> 90,15.8
> 95,15.4
> 100,15.4
> 
> Question:  where would you put the ink limit based on these data, and why?
> 
> Thanks.
> 
> --John
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
>

--- In QuadtoneRIP@yahoogroups.com, "Tom Moore" <r.t.moore@r...> wrote:
 
> I was not happy with the curves and stopped working on them. In the 
> end I decided that the 95% Black Boost is too high because I was 
> getting ink spattering near the edges of the blacks. 

Tom,

Thanks for this info.  What were you not happy about for your curves?
 What would you recommend trying based on your experience?

--John

John

The spattering was a problem for me. I realized that I would have to set a
lower value for black boost (and perhaps live with the lower dmax that might
result) and then go back and re-linearize. I may do that sometime. I'm more
interested in UT7 inks right now.

Tom Moore

> -----Original Message-----
> From: QuadtoneRIP@yahoogroups.com [mailto:QuadtoneRIP@yahoogroups.com] On
> Behalf Of John Hollenberg
> Sent: Saturday, October 22, 2005 8:52 AM
> To: QuadtoneRIP@yahoogroups.com
> Subject: [QuadtoneRIP] Re: Where to Set Ink Limit?
> 
> --- In QuadtoneRIP@yahoogroups.com, "Tom Moore" <r.t.moore@r...> wrote:
> 
> > I was not happy with the curves and stopped working on them. In the
> > end I decided that the 95% Black Boost is too high because I was
> > getting ink spattering near the edges of the blacks.
> 
> Tom,
> 
> Thanks for this info.  What were you not happy about for your curves?
>  What would you recommend trying based on your experience?
> 
> --John
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
>

--- In QuadtoneRIP@yahoogroups.com, "Tom Moore" <r.t.moore@r...> wrote:

> The spattering was a problem for me. I realized that I would have to 
> set a lower value for black boost (and perhaps live with the lower 
> dmax that might result) and then go back and re-linearize. I may do 
> that sometime. I'm more interested in UT7 inks right now.

Can you describe this "spattering" a bit more?  I am working on a
porfile for EVFA now.  I set default ink limit a bit higher (80) and
getting the toning right before Black Boost (may only go to 90) and
linearizing.

How do you find the UT7 inks compared to UC?  I may go that direction
in the future.

Also, it would be nice to have the very helpful tutorial you wrote
expanded a bit.  Seems like there are a lot of pearls hidden in the
forum that would be best in the User Guide.  I know, you have a lot of
spare time available :-)

--John