QTR-Quadtone RIP

Tyler, the approach can vary a lot based of the ink set you are using.
 Most of the builtin
features are for inks with simple dilutions.

The last bunch of curves I did were for the 3800-UC.  Most of them are
very simple:
warm = just K's,   cool = just add C,LC,M,LM with simple tweaks of ink limits.
neutral was more effort to account for variations of color in the
light/dark inks.  See: UCmk-raw-neut.txt
here I used the CURVE with coordinates for subtle tweaking.  The nice
thing about this rather
than .acv's or .raw's is that it's all in one file.  If you like the
PS curve editing do it with .acv's
as you are working on the curve and then just transcribe the points
later on.  BTW, the QTR points
allow more of them and more accuracy using decimal values than the PS point.

Use the builtin features first to get close -- they all work very
smoothly.  Use the points for
the subtle variations.  Of course with other situations you can go to
the extreme of
hand coding all the coordinates for all of the inks.  Paul Roark did
this quite a bit with the 3MK
ink set since the "ink concept" was different.

Roy

On Fri, May 15, 2009 at 6:50 PM, Tyler Boley <tyler@...> wrote:
> Roy, I guess the next most obvious question, then, is- how are the ongoing new ink setups for QTR being developed in terms of the toner curves then?
> I just assumed the best way was to make a new .raw to use, but it sounds like this may be now an archaic method? Is there a better 2009 method?
> Thanks,
> T
>
> --- In QuadtoneRIP@yahoogroups.com, Roy Harrington <roy@...> wrote:
>>
>> Hi Tyler,
>>
>> It's been so long since I had to use the .raw files I had to re-check it out.
>> The rgb-raw-16.psd file is really for the custom RGB curves in the ICC profiles.
>>
>> For the simple curve .raw you ought to use a gray version i.e. just one channel.
>> You can convert gray in PS but make sure the CM working spaces are compatible.
>> It's imperative that you get the same 256 levels.  Check histogram
>> after conversion.
>> You are also right about the reversal -- the file should go from white
>> to black i.e.
>> the way we think of "ink" curves not the RGB concept of light - black to white.
>>
>> Roy
>>
>> On Thu, May 14, 2009 at 11:43 AM, Tyler Boley <tyler@...> wrote:
>> > thanks, this is what I presumed.
>> > All I wanted to do was get some nasty spikes out of the toner channels down near 100% in the existing curves I've been trying.
>> > They are only a problem with some of the PK setups, giving less than ideal gloss differential performance between 90 and 100%.
>> >
>> > Regarding creating new raws, should the base file used be rgb-raw-16.psd? It looks to me like the existing raw toner files have been rotated 180% from that.
>> > Does it matter?
>> > Tyler
>> >
>> > --- In QuadtoneRIP@yahoogroups.com, Roy Harrington <roy@> wrote:
>> >>
>> >> The Density values are for partitioning multiple levels of toner i.e. M and LM.
>> >> The dark one or a single toner would be 100.
>> >>
>> >> I would start with the highlight/shadow values the same as the ones in the
>> >> gray channel.  This gives close to a constant ratio of toner-to-gray ink.
>> >> After that you can fine tune with small variations in highlight/shadow --
>> >> larger values give less toner and smaller ones give more toner.  You can
>> >> do split tone this way but I tend to leave splits to the print
>> >> sliders.  As Howard
>> >> mentions you can get fine control with custom .acv /.raw curves.
>> >>
>> >> Roy
>> >>
>> >> On Mon, May 11, 2009 at 6:08 PM, Tyler Boley <tyler@> wrote:
>> >> > I'm not seeing much info on doing more detailed toner content edits. Obviously the limit for overall amount of a given ink, but it's not clear to me what the density setting would be accomplishing in this context, on a single ink toner color.
>> >> > So, I'm assuming the highlight, shadow, and gamma setting offer some possibilites?
>> >> > Or further, editing a new raw file to use?
>> >> > Thanks,
>> >> > Tyler
>> >> >