QTR-Quadtone RIP

I am using an Epson 1280 with UT2 inks. I am following the user's
guide for creating curves and it says I need to find the relative
densities of all the black/gray inks in order from darkest to lightest. 

Which inks do you use for this? The cyan position has a bluish ink
that I suspect is considered a toner ink as does the light cyan. The
yellow position has yellow ink which I expect is also a toner. Do I
use Black, Magenta, Light Magenta in that order as my Black/Gray inks
and consider the others as toners?

I would very much appreciate any direction on this.

Thank you.

Scott

Scott

The general idea would be to make two curves - one using K (black), C & 
LC for a cool(bluish) tone curve and the other using K, M & LM for a 
warm tone curve. You can then use qtr's ability to blend two curves at 
print time to produce the degree of warmth/coolness you favour.

The yellow position ink is for a sepia tone and is used generally as a 
toner ink.

There should be other examples of curves designed for either UT2 or UT7 
that you can look at (see for example the UT7 curves for the 2200). 
Remember though that the UT7 curves have the warm & cool inks round the 
other way (ie cool in M/LM, warm in C/LC).

Howard


None wrote:

> I am using an Epson 1280 with UT2 inks. I am following the user's
> guide for creating curves and it says I need to find the relative
> densities of all the black/gray inks in order from darkest to lightest.
> 
> Which inks do you use for this? The cyan position has a bluish ink
> that I suspect is considered a toner ink as does the light cyan. The
> yellow position has yellow ink which I expect is also a toner. Do I
> use Black, Magenta, Light Magenta in that order as my Black/Gray inks
> and consider the others as toners?
> 
> I would very much appreciate any direction on this.
> 
> Thank you.
> 
> Scott
>

Howard,

Thank you for the reply. Loading up an existing curve along with your
explaination helped alot. 

Since the existing curve had values so close to what I measured I
decided to use it as is except clear the linearization values and
relinearize. 

I printed the 21 step wedge and measured the values with my spectro.
Oddly the 100% patch only read a density of 1.603 where the 100% black
patch from the calibration/separation page reads 1.701. That is a big
difference but I figured that linearizing would fix it.

After linearizing the 21 step target has beautiful separation all the
way through and looks very good. Except... the 100% black patch still
measures 1.61. This does not seem near what this paper/ink combo can
achieve (UT2 on Innova Fiba-Print) since I measured over 1.7 on the
separation page. The ink limit is set to 70% and the black boost is 100. 

Is this normal? Should I expect to be able to get a DMax of 1.7???

Thanks.

Scott

--- In QuadtoneRIP@yahoogroups.com, Howard Shaw <glassman@b...> wrote:
>
> Scott
> 
> The general idea would be to make two curves - one using K (black), C & 
> LC for a cool(bluish) tone curve and the other using K, M & LM for a 
> warm tone curve. You can then use qtr's ability to blend two curves at 
> print time to produce the degree of warmth/coolness you favour.
> 
> The yellow position ink is for a sepia tone and is used generally as a 
> toner ink.
> 
> There should be other examples of curves designed for either UT2 or UT7 
> that you can look at (see for example the UT7 curves for the 2200). 
> Remember though that the UT7 curves have the warm & cool inks round the 
> other way (ie cool in M/LM, warm in C/LC).
> 
> Howard
> 
> 
> None wrote:
> > I am using an Epson 1280 with UT2 inks. I am following the user's
> > guide for creating curves and it says I need to find the relative
> > densities of all the black/gray inks in order from darkest to
lightest.

> > 
> > Which inks do you use for this? The cyan position has a bluish ink
> > that I suspect is considered a toner ink as does the light cyan. The
> > yellow position has yellow ink which I expect is also a toner. Do I
> > use Black, Magenta, Light Magenta in that order as my Black/Gray inks
> > and consider the others as toners?
> > 
> > I would very much appreciate any direction on this.
> > 
> > Thank you.
> > 
> > Scott
> >
>

Scott,

 > I printed the 21 step wedge and measured the values with my spectro.
 > Oddly the 100% patch only read a density of 1.603 where the 100% black
 > patch from the calibration/separation page reads 1.701. That is a big
 > difference but I figured that linearizing would fix it.
 >
 > After linearizing the 21 step target has beautiful separation all the
 > way through and looks very good. Except... the 100% black patch still
 > measures 1.61. This does not seem near what this paper/ink combo can
 > achieve (UT2 on Innova Fiba-Print) since I measured over 1.7 on the
 > separation page. The ink limit is set to 70% and the black boost is 100.
 >
 > Is this normal? Should I expect to be able to get a DMax of 1.7???
 >

This is a common problem and you will find various discussions relating 
to dmax if you search through the archives. I would start by looking at 
the overlap figure on the gray curve tab. In theory a figure of 0 for 
overlap and 100% ink limit or black boost should give you exactly the 
same black patch reading as the calibration page. Figures greater than 
zero determine how much the inks overlap with each other including the 
black & darkest grey overlap. In other words some dark grey will be laid 
down with the black. Sometimes this helps dmax, sometimes it worsens it.

Another thing to consider is whether the readings for the 70% - 100% 
patches on the calibration page give you a consistent increase. If not 
you may be over-inking the paper and cannot expect to get consistent 
densities.

Howard

Howard,

Thank you again for the additional information. I'm starting to get a
little better feel for QTR. I have been playing around but so far
nothing seems to give me a significant increase in dmax. It could be
that I'm getting all I can out of this Innova paper. Perhaps I need to
order some paper that is known to have better dmax to start with.

Has anyone out there created curves for Innova Fiba-Print and UT2 inks
on a 1280? If so I would love to hear from you.

I did check the ink densities for black and found that they do max out
around 85% with a only a slight increase beyond that. So I'm assuming
that there is no point in setting a black boost beyond 85%. But that
value is over 1.7 and I'm only seeing about 1.61 for all my troubles.
I'm curious what approach the experienced QTR user would take from
here. Would you remove the overlap first? Is there a particular order
to changing settings that would be recommended?

Thanks for the help.

Scott

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

> This is a common problem and you will find various discussions relating 
> to dmax if you search through the archives. I would start by looking at 
> the overlap figure on the gray curve tab. In theory a figure of 0 for 
> overlap and 100% ink limit or black boost should give you exactly the 
> same black patch reading as the calibration page. Figures greater than 
> zero determine how much the inks overlap with each other including the 
> black & darkest grey overlap. In other words some dark grey will be
laid 

> down with the black. Sometimes this helps dmax, sometimes it worsens it.
> 
> Another thing to consider is whether the readings for the 70% - 100% 
> patches on the calibration page give you a consistent increase. If not 
> you may be over-inking the paper and cannot expect to get consistent 
> densities.
> 
> Howard
>