QTR-Quadtone RIP

Thanks for this clear - as far as it goes - explanation. And despite
what follows, I am really truly grateful for your answer to my question.

Why do I say "as far as it goes"? I think what I am missing is a good
overview and under-the-hood-view of the subject, something I would get
in a published book (I don't know of any) or an advanced course on
digital black and white printing (not offered in my community
college). I'm sure with this under-the-hood knowledge all would come
clear.

I know in color printing what I am accomplishing when I create a .icc
profile: I'm recording the response of my
printer/ink/paper/resolution/etc. combination to a request to print a
certain RGB value and making that information available to Photoshop
so it can compensate when it sends a file to the printer. 

Now, what am I accomplishing when I create an Epson ABW profile?
Presumably the same thing, except I am measuring shades of gray
instead of colors.

That's overview. Under the hood, I know the spectrophotometer measures
the RGB values actually printed. For color, the Eye-one software
somehow magically turns those numbers into a .icc profile. For
grayscale, the MeasureTool software somehow magically creates a
mysterious text file full of mysterious numbers, which QTR CreateICC
magically turns into a .icc profile. Photoshop reads the .icc profile
and adjusts the numbers sent to the printer so the printer prints the
colors or shades of gray Photoshop expects the original numbers to
represent.

Now we come to QTR curves/profiles, non-Epson ink sets, mysterious
terms like "linearization," "ink limit," "density," "L values," etc.
And unclear actions such as entering values into a curve in QTR. All
the information I can find on the Web and in news groups and in QTR
documentation appears to take for granted that the reader has an
overview and under-the-hood-view of what QTR is doing. I don't; that's
why I asked for a "For dummies" explanation. 

I know I'm asking too much for any individual to give me a semester's
tutorial for free -- but can anyone point me to a book or on-line
class or, I suppose, tutorial video, or even an in-person workshop
that explains this material, with particular reference to QTR and the
terms used? 

 - confused susan trying to figure it all out

--- In QuadtoneRIP@yahoogroups.com, "Michael T. Murphy"
<uriel_bear@...> wrote:
>
> > but I haven't figured out how to
> > "print without linearize values, measure, and 
> > put the values into a curve."
> > And that's why I'm not using QTR..
> > 
> 
> That assumes that you have followed the first couple of steps in 
> setting up a new curve.  Basically you should have already done the 
> following:
> 
> 1) Print out the the step chart for all of the inks, with no ink 
> limit set, using the QTR "Calibration Mode." Then,
> 
> 2) Determine the black ink limit from that chart.  Set the limit in 
> QTR. Print out the step charts a second time with that limit set.
> 
> 3) Go to "Curve Creation" in QTR. Use the 1st and 2nd chart to 
> determine the "Density" and "Limit" for each of the other black/grey 
> inks.  Save the curve set that you are working on.  (Paul Roark has 
> some pretty good instructions for all of this on his web site.)
> 
> 
> Once you are at that point, go into QTR and open up the 21 Step 
> chart.  
> 
> 4) Select the curve set that you are working on.  Set the dpi, etc. 
> that you want to use later for your prints.  Print out the 21 Step 
> chart with that curve.
> 
> 5) Open the Gretag ProfileMaker software. Use the "Measure" function. 
> Use a spectrophotometer to read the "L" values of each patch on the 
> 21 step chart that you just printed.
> 
> 6) Export the "L" values to a text file.  Open the text file, cut and 
> paste the values to Excel.  Copy just the "L" values from Exzcel.
> 
> 7) Paste the L values on the "Linerization" tab of teh curve that you 
> are making in QTR.  Save the file.  Generate the curves.
> 
> 
> A few points. If you have gotten to the stage of making your own ICC 
> profile using the QTR "Create ICC" tool, you should already be 
> through step #6?  You should have created a text file from the 21 
> step chart that you dragged to the "Create ICC" tool?  Then it is 
> just a matter of entering those values in the curve that you are 
> creating in QTR.
> 
> One question though: what papers are you using? Which inks? Aren't 
> there existng profiles in QTR for the 3800 and a paper close to teh 
> one tht you are using? The curves don't vary a lot from paper to 
> paper.
> 
> Hope that helps.  No time to re-read - hope it all makes sense 
> too. ;>) Post questions. Good luck!
> 
> Best,
> Michael
>