QTR-Quadtone RIP

I have a simple problem:  I was getting ink bleeding with Cone
supplied quad file for HPR and NK7 inks on my 2200.  So, I took the
qidf file that is supplied with QTR for HPR 1440 and went to
relinearize it for 2880.  Unfortunately, it turns out the 2880 puts
down more ink so that the patch with the lowest L* is actually the 90
patch rather than the 100.  The qidf file came with ink limit of 75
and black boost of 95.  Is there a simple guestimate of what I should
change with the ink limit in order to avoid the overinking?  My own
guess is to take 90% of the 95 black boost limit (=85.5) and set that
as the black boost.  Is that a good guess

Thanks.

--John

All I can tell is you is that 1440 profile is nothing like the 2880.
You can't make the kind of curves in the 2880 profile from tools in QTR.
If you right click the profile in QTRgui (if you are on windows), you'll see
what the 1440 curves look like.
The 1440 has inklimit up there at 75 with that black boost.
Notice on the 1440 profile it's just LK and K 95-100
On the 2880 curve it's FIVE inks in that region.
They are just two totally different beasts.
Scott


On 1/15/07, John Hollenberg <weasel@...> wrote:
>
>   I have a simple problem: I was getting ink bleeding with Cone
> supplied quad file for HPR and NK7 inks on my 2200. So, I took the
> qidf file that is supplied with QTR for HPR 1440 and went to
> relinearize it for 2880. Unfortunately, it turns out the 2880 puts
> down more ink so that the patch with the lowest L* is actually the 90
> patch rather than the 100. The qidf file came with ink limit of 75
> and black boost of 95. Is there a simple guestimate of what I should
> change with the ink limit in order to avoid the overinking? My own
> guess is to take 90% of the 95 black boost limit (=85.5) and set that
> as the black boost. Is that a good guess
>
> Thanks.
>
> --John
>
> 
>


[Non-text portions of this message have been removed]

Scott,

Very helpful.  I didn't know I could look at the 2880 curves in that
way.  I do have the Bowhaus RIP and may give that a try, although that
could be more complicated. Wonder how they decided on those strange
curves!  

So far, cutting the black boost to 85 has been helpful, but not quite
enough.  I am currently trying 75.  It seems that the overlap of
multiple inks may be to control the a* and b* readings (which I
noticed were modestly different in the shape of the curve from L*
0-100 compared to the a* and b* readings for the profile built by
Cone.  Looks like I can solve the dmax problem, but not necessarily
the subtle tonings, with QTR.

Thanks.

--John

John

There are two ways you can go about doing what you want. You can adjust the
1440 curve. To do that I would start by reducing all the limits by 85% and
then further adjusting the black boost for highest dmax without bleeding.
Then you would have to re-linearize. It's true that the Cone supplied curves
are different from those that can be produced by QTR. At least with QTR
derived curves you have the ability to make changes to correct problems like
the one you're encountering. 

Another approach would be to use the existing 2880 curve and reducing the
QTR Ink Limit Adjustment (in the print window) until the bleeding is
eliminated. Assuming the resulting dmax is still acceptable, you could then
re-linearize for that ink limit by creating an ICC file using
QTR_Create_ICC.

Good luck.

Tom Moore

> -----Original Message-----
> From: QuadtoneRIP@yahoogroups.com [mailto:QuadtoneRIP@yahoogroups.com] On
> Behalf Of John Hollenberg
> Sent: Monday, January 15, 2007 7:53 PM
> To: QuadtoneRIP@yahoogroups.com
> Subject: [QuadtoneRIP] Help Changing Ink Limits for Profile
> 
> I have a simple problem:  I was getting ink bleeding with Cone
> supplied quad file for HPR and NK7 inks on my 2200.  So, I took the
> qidf file that is supplied with QTR for HPR 1440 and went to
> relinearize it for 2880.  Unfortunately, it turns out the 2880 puts
> down more ink so that the patch with the lowest L* is actually the 90
> patch rather than the 100.  The qidf file came with ink limit of 75
> and black boost of 95.  Is there a simple guestimate of what I should
> change with the ink limit in order to avoid the overinking?  My own
> guess is to take 90% of the 95 black boost limit (=85.5) and set that
> as the black boost.  Is that a good guess

...
>

--- In QuadtoneRIP@yahoogroups.com, "Tom Moore" <r.t.moore@...> wrote:
 
> There are two ways you can go about doing what you want. You can 
> adjust the 1440 curve. To do that I would start by reducing all the 
> limits by 85% and then further adjusting the black boost for highest
> dmax without bleeding.
> Then you would have to re-linearize. It's true that the Cone 
> supplied curves are different from those that can be produced by 
> QTR. At least with QTR derived curves you have the ability to make 
> changes to correct problems like the one you're encountering. 

Why would one want to decrease all of the ink limits?  Are you talking
about setting the default ink limit to 85% of what it was (which was
75%), or 64%)?  So far I have had some success by just decreasing the
black boost to fix the overinking in the shadows.

> Another approach would be to use the existing 2880 curve and 
> reducing the QTR Ink Limit Adjustment (in the print window) until 
> the bleeding is eliminated. Assuming the resulting dmax is still 
> acceptable, you could then re-linearize for that ink limit by 
> creating an ICC file using QTR_Create_ICC.

This sounds like a better solution, since it would fix the problem
(hopefully) while still preserving the rest of the Cone profile and
the careful toning.  Does this just affect the black ink?  Are the
numbers the amount to decrease the ink limit for that black ink?

Thanks.

--John

--- In QuadtoneRIP@yahoogroups.com, "Scott Schroeder" <schrochem@...> 
wrote:
>
> All I can tell is you is that 1440 profile is nothing like the 2880.

That's true indeed. Originaly I started of with 1440 dpi on my Epson 
2100/UT3D/windows/QTR setup, but now I'm changing towards 2980 dpi. No 
way that I can re-use the 1440 dpi.

> You can't make the kind of curves in the 2880 profile from tools in 
QTR.

I don't understand this remark. I have no experience with the NK7, but 
why not just building a new curve from the ground following the 
procedure outlined in Tom Moore's user manual? Since you're not 
bothered by tonality issues with NK7 that should be a straightforward 
thing to do. 

Joost

>
> > You can't make the kind of curves in the 2880 profile from tools in
> QTR.
>
> I don't understand this remark. I have no experience with the NK7, but
> why not just building a new curve from the ground following the
> procedure outlined in Tom Moore's user manual? Since you're not
> bothered by tonality issues with NK7 that should be a straightforward
> thing to do.
>
> Joost

I didn't mean you couldn't make curves. I was just saying you can't
make curves that have the nice transitions and crossovers that are in
the supplied curves.
This message will explain it better:
http://tech.groups.yahoo.com/group/QuadtoneRIP/message/1165

Scott

OK, I am getting close.  Here are the values I arrived at which
produce a good dmax (L* = 16.62) and have a* and b* quite similar to
the Cone curve.  There is still a bit of a problem with the b* in the
shadow area (goes up to 1.5, Cone is 0.2) and in the highlight area
(goes down to -1.5, Cone is -0.5), but getting close.  For anyone who
is interested, here are my values:

Default ink limit - 55
Black boost - blank

Black 100, 40 (Density, Limit)
Cyan 28, 35
Magenta 6.8, 40
Yellow 1.5 45
Light Cyan 17, 37
Light Magenta 3, 40
Light Black 45, 40

Highlight 10
Shadow 10
Overlap 100
Gamma 1

Plug them in and see what the curves look like.

Comments and suggestions welcome.

--John

Scott Schroeder wrote:
>>
>> > You can't make the kind of curves in the 2880 profile from tools in
>> QTR.
>>
>> I don't understand this remark. I have no experience with the NK7, but
>> why not just building a new curve from the ground following the
>> procedure outlined in Tom Moore's user manual? Since you're not
>> bothered by tonality issues with NK7 that should be a straightforward
>> thing to do.
>>
>> Joost
> 
> I didn't mean you couldn't make curves. I was just saying you can't
> make curves that have the nice transitions and crossovers that are in
> the supplied curves.
> This message will explain it better:
> http://tech.groups.yahoo.com/group/QuadtoneRIP/message/1165
> 
> Scott
> 
> 
You can...use the Load Curve facility for all inks and import .acv files 
in the shape of the curves you want. The curves will scale for the ink 
limits you set and linearisation still appears to work without altering 
the basic shapes. This method of working is more akin to that found in 
Bowhaus.

Howard

--- In QuadtoneRIP@yahoogroups.com, "Scott Schroeder" <schrochem@...> 
wrote:

> I didn't mean you couldn't make curves. I was just saying you can't
> make curves that have the nice transitions and crossovers that are 
in
> the supplied curves.
> This message will explain it better:
> http://tech.groups.yahoo.com/group/QuadtoneRIP/message/1165

Thanks Scott, that explains your remarks indeed. But for my 
information: does it make in practice REALLY any difference whether 
you use these original PiezoBW curves in stead of making your own 
curves with QTR? Since I'm printing on 2880 dpi with QTR/2100/UT3D 
I've a hard time to find any grain in my prints. So, imho on that 
aspect I expect there is little left to improve by going to 7 inks. 
But even if so, do the details of the curve then still make a 
difference on top of that? Or does the claimed smoothness of the NK7 
inks ONLY appear with the custom PiezoBW curves? 

 Joost

Joost

If you have a look at the Cone-made k7 curves (the 2880dpi ones) they 
are differently constructed to the type of curves that qtr makes.

I've made a web page showing the difference and also how the Load curves 
facility in qtr can be used to emulate the type of curves produced by 
Cone's proprietary method.

http://www.howardshaw.org/docs/k7-qtr/k7curves.htm

The main difference is that the normal qtr curve creation method using 
density boundaries usually only allows 3 inks to overlap at a time 
whereas the Cone curves have upto 5 overlapping inks. On the basis that 
the more jets firing the better this should lead to a smoother print.

Note that I do not have the K7 inks so this is a technical exercise only.

Howard

Joost Horsten wrote:

> --- In QuadtoneRIP@yahoogroups.com, "Scott Schroeder" <schrochem@...> 
> wrote:
> 
>> I didn't mean you couldn't make curves. I was just saying you can't
>> make curves that have the nice transitions and crossovers that are 
> in
>> the supplied curves.
>> This message will explain it better:
>> http://tech.groups.yahoo.com/group/QuadtoneRIP/message/1165
> 
> Thanks Scott, that explains your remarks indeed. But for my 
> information: does it make in practice REALLY any difference whether 
> you use these original PiezoBW curves in stead of making your own 
> curves with QTR? Since I'm printing on 2880 dpi with QTR/2100/UT3D 
> I've a hard time to find any grain in my prints. So, imho on that 
> aspect I expect there is little left to improve by going to 7 inks. 
> But even if so, do the details of the curve then still make a 
> difference on top of that? Or does the claimed smoothness of the NK7 
> inks ONLY appear with the custom PiezoBW curves? 
> 
>  Joost
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>

I assume this is only for the PC version or is there a way to use  
the .acv curves with the Mac version of QTR?

Carl

On Jan 16, 2007, at 5:44 PM, Howard Shaw wrote:

> Joost
>
> If you have a look at the Cone-made k7 curves (the 2880dpi ones) they
> are differently constructed to the type of curves that qtr makes.
>
> I've made a web page showing the difference and also how the Load  
> curves
> facility in qtr can be used to emulate the type of curves produced by
> Cone's proprietary method.
>
> http://www.howardshaw.org/docs/k7-qtr/k7curves.htm
>
> The main difference is that the normal qtr curve creation method using
> density boundaries usually only allows 3 inks to overlap at a time
> whereas the Cone curves have upto 5 overlapping inks. On the basis  
> that
> the more jets firing the better this should lead to a smoother print.
>
> Note that I do not have the K7 inks so this is a technical exercise  
> only.
>
> Howard
>
> Joost Horsten wrote:
>> --- In QuadtoneRIP@yahoogroups.com, "Scott Schroeder" <schrochem@...>
>> wrote:
>>
>>> I didn't mean you couldn't make curves. I was just saying you can't
>>> make curves that have the nice transitions and crossovers that are
>> in
>>> the supplied curves.
>>> This message will explain it better:
>>> http://tech.groups.yahoo.com/group/QuadtoneRIP/message/1165
>>
>> Thanks Scott, that explains your remarks indeed. But for my
>> information: does it make in practice REALLY any difference whether
>> you use these original PiezoBW curves in stead of making your own
>> curves with QTR? Since I'm printing on 2880 dpi with QTR/2100/UT3D
>> I've a hard time to find any grain in my prints. So, imho on that
>> aspect I expect there is little left to improve by going to 7 inks.
>> But even if so, do the details of the curve then still make a
>> difference on top of that? Or does the claimed smoothness of the NK7
>> inks ONLY appear with the custom PiezoBW curves?
>>
>>  Joost
>>

Hi Carl,

It's easy to do on the Mac, too.     Just use:
CURVE_K=k7_black.acv
CURVE_LM=k7_ltmagenta.acv
etc...

Howard's idea is an interesting possibility.   You could design the 
basic curve
shapes this way and then linearize the result.   The potential 
difficulty would be
that you get some flat spots or extra wiggles in the density curve.   
Just because
the look smooth doesn't mean the sum on the curves with different inks 
would
also look that smooth.  The linearize can fix only so much.   In the 
specific example
it probably would work well since they are designed from existing 
"good" profiles.

Since the K7 inks are so close in density you can have the very large 
overlaps
-- ie. 5 inks instead of just 3.   There is also some benefit in the 
2880dpi because its
only one dotsize.   At 1440 there will be 2 or 3 dotsizes used which 
results in more
transitions.

For anyone wanting to customize their own K7 ink profiles a very nice 
approach is
to take advantage of the piezo k7 profiles and then build ICC profiles 
on top of
them.  This way you get full color management from screen to print with 
softproofing
as well.

Roy

On Tuesday, January 16, 2007, at 03:14  PM, Carl Schofield wrote:

> I assume this is only for the PC version or is there a way to use
> the .acv curves with the Mac version of QTR?
>
> Carl
>
> On Jan 16, 2007, at 5:44 PM, Howard Shaw wrote:
>
>> Joost
>>
>> If you have a look at the Cone-made k7 curves (the 2880dpi ones) they
>> are differently constructed to the type of curves that qtr makes.
>>
>> I've made a web page showing the difference and also how the Load
>> curves
>> facility in qtr can be used to emulate the type of curves produced by
>> Cone's proprietary method.
>>
>> http://www.howardshaw.org/docs/k7-qtr/k7curves.htm
>>
>> The main difference is that the normal qtr curve creation method using
>> density boundaries usually only allows 3 inks to overlap at a time
>> whereas the Cone curves have upto 5 overlapping inks. On the basis
>> that
>> the more jets firing the better this should lead to a smoother print.
>>
>> Note that I do not have the K7 inks so this is a technical exercise
>> only.
>>
>> Howard
>>
>> Joost Horsten wrote:
>>> --- In QuadtoneRIP@yahoogroups.com, "Scott Schroeder" <schrochem@...>
>>> wrote:
>>>
>>>> I didn't mean you couldn't make curves. I was just saying you can't
>>>> make curves that have the nice transitions and crossovers that are
>>> in
>>>> the supplied curves.
>>>> This message will explain it better:
>>>> http://tech.groups.yahoo.com/group/QuadtoneRIP/message/1165
>>>
>>> Thanks Scott, that explains your remarks indeed. But for my
>>> information: does it make in practice REALLY any difference whether
>>> you use these original PiezoBW curves in stead of making your own
>>> curves with QTR? Since I'm printing on 2880 dpi with QTR/2100/UT3D
>>> I've a hard time to find any grain in my prints. So, imho on that
>>> aspect I expect there is little left to improve by going to 7 inks.
>>> But even if so, do the details of the curve then still make a
>>> difference on top of that? Or does the claimed smoothness of the NK7
>>> inks ONLY appear with the custom PiezoBW curves?
>>>
>>>  Joost
>>>
>
>
-
Roy Harrington
roy@...
Black & White Photo Gallery
http://www.harrington.com

Thanks Roy.  I didn't know what the syntax was for the curves  
functions.  I have K7 inks loaded in my 2400 so I'll give this  
approach a try.

Carl

On Jan 16, 2007, at 7:07 PM, Roy Harrington wrote:

> Hi Carl,
>
> It's easy to do on the Mac, too.     Just use:
> CURVE_K=k7_black.acv
> CURVE_LM=k7_ltmagenta.acv
> etc...
>
> Howard's idea is an interesting possibility.   You could design the
> basic curve
> shapes this way and then linearize the result.   The potential
> difficulty would be
> that you get some flat spots or extra wiggles in the density curve.
> Just because
> the look smooth doesn't mean the sum on the curves with different inks
> would
> also look that smooth.  The linearize can fix only so much.   In the
> specific example
> it probably would work well since they are designed from existing
> "good" profiles.
>
> Since the K7 inks are so close in density you can have the very large
> overlaps
> -- ie. 5 inks instead of just 3.   There is also some benefit in the 
> 2880dpi because its
> only one dotsize.   At 1440 there will be 2 or 3 dotsizes used which
> results in more
> transitions.
>
> For anyone wanting to customize their own K7 ink profiles a very nice
> approach is
> to take advantage of the piezo k7 profiles and then build ICC profiles
> on top of
> them.  This way you get full color management from screen to print  
> with
> softproofing
> as well.
>
> Roy
>
> On Tuesday, January 16, 2007, at 03:14  PM, Carl Schofield wrote:
>
>> I assume this is only for the PC version or is there a way to use
>> the .acv curves with the Mac version of QTR?
>>
>> Carl
>>
>> On Jan 16, 2007, at 5:44 PM, Howard Shaw wrote:
>>
>>> Joost
>>>
>>> If you have a look at the Cone-made k7 curves (the 2880dpi ones)  
>>> they
>>> are differently constructed to the type of curves that qtr makes.
>>>
>>> I've made a web page showing the difference and also how the Load
>>> curves
>>> facility in qtr can be used to emulate the type of curves  
>>> produced by
>>> Cone's proprietary method.
>>>
>>> http://www.howardshaw.org/docs/k7-qtr/k7curves.htm
>>>
>>> The main difference is that the normal qtr curve creation method  
>>> using
>>> density boundaries usually only allows 3 inks to overlap at a time
>>> whereas the Cone curves have upto 5 overlapping inks. On the basis
>>> that
>>> the more jets firing the better this should lead to a smoother  
>>> print.
>>>
>>> Note that I do not have the K7 inks so this is a technical exercise
>>> only.
>>>
>>> Howard
>>>
>>> Joost Horsten wrote:
>>>> --- In QuadtoneRIP@yahoogroups.com, "Scott Schroeder"  
>>>> <schrochem@...>
>>>> wrote:
>>>>
>>>>> I didn't mean you couldn't make curves. I was just saying you  
>>>>> can't
>>>>> make curves that have the nice transitions and crossovers that are
>>>> in
>>>>> the supplied curves.
>>>>> This message will explain it better:
>>>>> http://tech.groups.yahoo.com/group/QuadtoneRIP/message/1165
>>>>
>>>> Thanks Scott, that explains your remarks indeed. But for my
>>>> information: does it make in practice REALLY any difference whether
>>>> you use these original PiezoBW curves in stead of making your own
>>>> curves with QTR? Since I'm printing on 2880 dpi with QTR/2100/UT3D
>>>> I've a hard time to find any grain in my prints. So, imho on that
>>>> aspect I expect there is little left to improve by going to 7 inks.
>>>> But even if so, do the details of the curve then still make a
>>>> difference on top of that? Or does the claimed smoothness of the  
>>>> NK7
>>>> inks ONLY appear with the custom PiezoBW curves?
>>>>
>>>>  Joost
>>>>

Howard,

The LK curve does not seem to be in the correct position- it should  
fall between the Y and LM curves.  I'm using the 2400, so perhaps ink  
assignments are different?

Carl

On Jan 16, 2007, at 5:44 PM, Howard Shaw wrote:

> Joost
>
> If you have a look at the Cone-made k7 curves (the 2880dpi ones) they
> are differently constructed to the type of curves that qtr makes.
>
> I've made a web page showing the difference and also how the Load  
> curves
> facility in qtr can be used to emulate the type of curves produced by
> Cone's proprietary method.
>
> http://www.howardshaw.org/docs/k7-qtr/k7curves.htm
>
> The main difference is that the normal qtr curve creation method using
> density boundaries usually only allows 3 inks to overlap at a time
> whereas the Cone curves have upto 5 overlapping inks. On the basis  
> that
> the more jets firing the better this should lead to a smoother print.
>
> Note that I do not have the K7 inks so this is a technical exercise  
> only.
>
> Howard
>
> Joost Horsten wrote:
>> --- In QuadtoneRIP@yahoogroups.com, "Scott Schroeder" <schrochem@...>
>> wrote:
>>
>>> I didn't mean you couldn't make curves. I was just saying you can't
>>> make curves that have the nice transitions and crossovers that are
>> in
>>> the supplied curves.
>>> This message will explain it better:
>>> http://tech.groups.yahoo.com/group/QuadtoneRIP/message/1165
>>
>> Thanks Scott, that explains your remarks indeed. But for my
>> information: does it make in practice REALLY any difference whether
>> you use these original PiezoBW curves in stead of making your own
>> curves with QTR? Since I'm printing on 2880 dpi with QTR/2100/UT3D
>> I've a hard time to find any grain in my prints. So, imho on that
>> aspect I expect there is little left to improve by going to 7 inks.
>> But even if so, do the details of the curve then still make a
>> difference on top of that? Or does the claimed smoothness of the NK7
>> inks ONLY appear with the custom PiezoBW curves?
>>
>>  Joost
>>

Carl Schofield wrote:
> Howard,
> 
> The LK curve does not seem to be in the correct position- it should  
> fall between the Y and LM curves.  I'm using the 2400, so perhaps ink  
> assignments are different?
> 
> Carl
> 
> On Jan 16, 2007, at 5:44 PM, Howard Shaw wrote:
> 
Carl

This set up is for the 2200 so I guess the assignments are different. I 
should emphasise that this was only a technical exercise. My imitation 
of the pre-made cone curves is not perfect but the .acv's can be tweaked 
  in theory to exactly replicate those curves. They can also be 
linearised subject to the provisos that Roy mentioned.

In practical reality doing this sort of thing with a quadtone set up is 
probably more realistic as dead spots and non-linearities are less 
likely to occur (although still a possibility) and are easier to cure 
than with the larger number of inks.

In my brief experience with the Bowhaus RIP this is how things work 
except Bowhaus has it's own Curves editor where you can add points to 
the curve like the Curves facility in photoshop.

Howard

--- In QuadtoneRIP@yahoogroups.com, Howard Shaw <glassman@...> wrote:

> 
> If you have a look at the Cone-made k7 curves (the 2880dpi ones) 
they 
> are differently constructed to the type of curves that qtr makes.
> 
> I've made a web page showing the difference and also how the Load 
curves 
> facility in qtr can be used to emulate the type of curves produced 
by 
> Cone's proprietary method.
> 
> http://www.howardshaw.org/docs/k7-qtr/k7curves.htm
> 
> The main difference is that the normal qtr curve creation method 
using 
> density boundaries usually only allows 3 inks to overlap at a time 
> whereas the Cone curves have upto 5 overlapping inks. On the basis 
that 
> the more jets firing the better this should lead to a smoother 
print.
> 

Ah, I see. I can imagine indeed this contributes to the overall 
smoothness. Thanks for the education ;-)

Howard's approach intriqued me so I gave it a shot from another way. I used
the 'load curve' option but pasted in 50 points for each ink. I did this for
the 2200 K7-2880-Hanphotorag profile. I uploaded the qidf to the files
section under curves/2100-2200 and it's called k7-test.qidf.  I hope that is
alright with Jon and/or Roy. If not feel free to take it down.
By visually comparing the curves they look the same. I would be interested
in your remark about 'flat spots' Roy and see if this would apply to this
qidf?  The cone curves use up to 255 points but the qtr interface only
allows for 50 so I chose an equal distribution throughout to maintain
integrity. The K only has 46 points so it should be a direct match, but an
ink like Magenta had 254 so it has only 1/5th the points. But I would think
50 points would still be enough to prevent any flat spots.

Scott


On 1/16/07, Roy Harrington <roy@...> wrote:
>
>   Hi Carl,
>
> It's easy to do on the Mac, too. Just use:
> CURVE_K=k7_black.acv
> CURVE_LM=k7_ltmagenta.acv
> etc...
>
> Howard's idea is an interesting possibility. You could design the
> basic curve
> shapes this way and then linearize the result. The potential
> difficulty would be
> that you get some flat spots or extra wiggles in the density curve.
> Just because
> the look smooth doesn't mean the sum on the curves with different inks
> would
> also look that smooth. The linearize can fix only so much. In the
> specific example
> it probably would work well since they are designed from existing
> "good" profiles.
>
> Since the K7 inks are so close in density you can have the very large
> overlaps
> -- ie. 5 inks instead of just 3. There is also some benefit in the
> 2880dpi because its
> only one dotsize. At 1440 there will be 2 or 3 dotsizes used which
> results in more
> transitions.
>
> For anyone wanting to customize their own K7 ink profiles a very nice
> approach is
> to take advantage of the piezo k7 profiles and then build ICC profiles
> on top of
> them. This way you get full color management from screen to print with
> softproofing
> as well.
>
> Roy
>
>
> On Tuesday, January 16, 2007, at 03:14 PM, Carl Schofield wrote:
>
> > I assume this is only for the PC version or is there a way to use
> > the .acv curves with the Mac version of QTR?
> >
> > Carl
> >
> > On Jan 16, 2007, at 5:44 PM, Howard Shaw wrote:
> >
> >> Joost
> >>
> >> If you have a look at the Cone-made k7 curves (the 2880dpi ones) they
> >> are differently constructed to the type of curves that qtr makes.
> >>
> >> I've made a web page showing the difference and also how the Load
> >> curves
> >> facility in qtr can be used to emulate the type of curves produced by
> >> Cone's proprietary method.
> >>
> >> http://www.howardshaw.org/docs/k7-qtr/k7curves.htm
> >>
> >> The main difference is that the normal qtr curve creation method using
> >> density boundaries usually only allows 3 inks to overlap at a time
> >> whereas the Cone curves have upto 5 overlapping inks. On the basis
> >> that
> >> the more jets firing the better this should lead to a smoother print.
> >>
> >> Note that I do not have the K7 inks so this is a technical exercise
> >> only.
> >>
> >> Howard
> >>
> >> Joost Horsten wrote:
> >>> --- In QuadtoneRIP@yahoogroups.com <QuadtoneRIP%40yahoogroups.com>,
> "Scott Schroeder" <schrochem@...>
> >>> wrote:
> >>>
> >>>> I didn't mean you couldn't make curves. I was just saying you can't
> >>>> make curves that have the nice transitions and crossovers that are
> >>> in
> >>>> the supplied curves.
> >>>> This message will explain it better:
> >>>> http://tech.groups.yahoo.com/group/QuadtoneRIP/message/1165
> >>>
> >>> Thanks Scott, that explains your remarks indeed. But for my
> >>> information: does it make in practice REALLY any difference whether
> >>> you use these original PiezoBW curves in stead of making your own
> >>> curves with QTR? Since I'm printing on 2880 dpi with QTR/2100/UT3D
> >>> I've a hard time to find any grain in my prints. So, imho on that
> >>> aspect I expect there is little left to improve by going to 7 inks.
> >>> But even if so, do the details of the curve then still make a
> >>> difference on top of that? Or does the claimed smoothness of the NK7
> >>> inks ONLY appear with the custom PiezoBW curves?
> >>>
> >>> Joost
> >>>
> >
> >
> -
> Roy Harrington
> roy@... <roy%40harrington.com>
> Black & White Photo Gallery
> http://www.harrington.com
>
>  
>


[Non-text portions of this message have been removed]

Scott,

I did something similar for the 2400 with K7 inks.  Very easy to make profiles for new 
papers using the generic curve descriptor file I made.  Just measure new K ink limit and 
re-linearize.  No need to partition the inks.  I have the ink descriptor file (txt file for Mac) if 
anyone wants to try it.

Carl
 
--- In QuadtoneRIP@yahoogroups.com, "Scott Schroeder" <schrochem@...> wrote:

>
> Howard's approach intriqued me so I gave it a shot from another way. I used
> the 'load curve' option but pasted in 50 points for each ink. I did this for
> the 2200 K7-2880-Hanphotorag profile. I uploaded the qidf to the files
> section under curves/2100-2200 and it's called k7-test.qidf.  I hope that is
> alright with Jon and/or Roy. If not feel free to take it down.
> By visually comparing the curves they look the same. I would be interested
> in your remark about 'flat spots' Roy and see if this would apply to this
> qidf?  The cone curves use up to 255 points but the qtr interface only
> allows for 50 so I chose an equal distribution throughout to maintain
> integrity. The K only has 46 points so it should be a direct match, but an
> ink like Magenta had 254 so it has only 1/5th the points. But I would think
> 50 points would still be enough to prevent any flat spots.
> 
> Scott
> 
> 
> On 1/16/07, Roy Harrington <roy@...> wrote:
> >
> >   Hi Carl,
> >
> > It's easy to do on the Mac, too. Just use:
> > CURVE_K=k7_black.acv
> > CURVE_LM=k7_ltmagenta.acv
> > etc...
> >
> > Howard's idea is an interesting possibility. You could design the
> > basic curve
> > shapes this way and then linearize the result. The potential
> > difficulty would be
> > that you get some flat spots or extra wiggles in the density curve.
> > Just because
> > the look smooth doesn't mean the sum on the curves with different inks
> > would
> > also look that smooth. The linearize can fix only so much. In the
> > specific example
> > it probably would work well since they are designed from existing
> > "good" profiles.
> >
> > Since the K7 inks are so close in density you can have the very large
> > overlaps
> > -- ie. 5 inks instead of just 3. There is also some benefit in the
> > 2880dpi because its
> > only one dotsize. At 1440 there will be 2 or 3 dotsizes used which
> > results in more
> > transitions.
> >
> > For anyone wanting to customize their own K7 ink profiles a very nice
> > approach is
> > to take advantage of the piezo k7 profiles and then build ICC profiles
> > on top of
> > them. This way you get full color management from screen to print with
> > softproofing
> > as well.
> >
> > Roy
> >
> >
> > On Tuesday, January 16, 2007, at 03:14 PM, Carl Schofield wrote:
> >
> > > I assume this is only for the PC version or is there a way to use
> > > the .acv curves with the Mac version of QTR?
> > >
> > > Carl
> > >
> > > On Jan 16, 2007, at 5:44 PM, Howard Shaw wrote:
> > >
> > >> Joost
> > >>
> > >> If you have a look at the Cone-made k7 curves (the 2880dpi ones) they
> > >> are differently constructed to the type of curves that qtr makes.
> > >>
> > >> I've made a web page showing the difference and also how the Load
> > >> curves
> > >> facility in qtr can be used to emulate the type of curves produced by
> > >> Cone's proprietary method.
> > >>
> > >> http://www.howardshaw.org/docs/k7-qtr/k7curves.htm
> > >>
> > >> The main difference is that the normal qtr curve creation method using
> > >> density boundaries usually only allows 3 inks to overlap at a time
> > >> whereas the Cone curves have upto 5 overlapping inks. On the basis
> > >> that
> > >> the more jets firing the better this should lead to a smoother print.
> > >>
> > >> Note that I do not have the K7 inks so this is a technical exercise
> > >> only.
> > >>
> > >> Howard
> > >>
> > >> Joost Horsten wrote:
> > >>> --- In QuadtoneRIP@yahoogroups.com <QuadtoneRIP%40yahoogroups.com>,
> > "Scott Schroeder" <schrochem@>
> > >>> wrote:
> > >>>
> > >>>> I didn't mean you couldn't make curves. I was just saying you can't
> > >>>> make curves that have the nice transitions and crossovers that are
> > >>> in
> > >>>> the supplied curves.
> > >>>> This message will explain it better:
> > >>>> http://tech.groups.yahoo.com/group/QuadtoneRIP/message/1165
> > >>>
> > >>> Thanks Scott, that explains your remarks indeed. But for my
> > >>> information: does it make in practice REALLY any difference whether
> > >>> you use these original PiezoBW curves in stead of making your own
> > >>> curves with QTR? Since I'm printing on 2880 dpi with QTR/2100/UT3D
> > >>> I've a hard time to find any grain in my prints. So, imho on that
> > >>> aspect I expect there is little left to improve by going to 7 inks.
> > >>> But even if so, do the details of the curve then still make a
> > >>> difference on top of that? Or does the claimed smoothness of the NK7
> > >>> inks ONLY appear with the custom PiezoBW curves?
> > >>>
> > >>> Joost
> > >>>
> > >
> > >
> > -
> > Roy Harrington
> > roy@... <roy%40harrington.com>
> > Black & White Photo Gallery
> > http://www.harrington.com
> >
> >  
> >
> 
> 
> [Non-text portions of this message have been removed]
>