QTR-Quadtone RIP

--- In QuadtoneRIP@yahoogroups.com, "Harry Burnett Jr" <HBURNETT@...>
wrote:

> 
>   Yes_ I have a reflection and transmission densitometer. I probably
am not
>   being clear enough to elicit an answer that is helpful. Let me try
again to
>   better explain what I am printing and how I use the print.
> 
>   I am using a homemade digital fluid in an Epson 1280. The paper
which is
>   printed is water slide decal paper. It is paper that has a heavy
layer of
>   dextrine ( water soluable glue that is used on stamps- before peel and
>   stick) Pigments imbeded in the digital fluid are finely ground
china ceramic
>   paint pigments. After the pigmented dot image is dried, it is
coated with a
>   flexable organic lacquer. This consolidates the dots and holds the
image
>   together. The paper with the coated decal is soaked in water to
disolve the
>   dextrine glue. The decal is transferred to a ceramic surface and
squeeged to
>   conform to surface curves. The decal coated ceramic is put into a
kiln and
>   fired to 1100 -1300 degrees F where all organics are consumed and the
>   ceramic color particals melt and fuse into and onto the ceramic
surface.
>   This produces a very long lasting and durable photo image.
> 
>   Now that is explained, let me call your attention to the printing
>   consideration I am trying to improve. The "DOT GAIN" is great,
very great!
>   The first big dot gain occurs on the water slide decal paper. The
next dot
>   gains occur during the firing phase. My present printing procedure
is to
>   manage the image so a good BW image shows on the monitor. I may
slightly
>   over sharpen, then desaturate and save as Tif. Next I apply a
strong curve
>   that makes the monitor image look almost white. I send this RGB
desatuated
>   image to the 1280 printer using black only, glossy color paper, at
gamma 1.5
>   settings. It does not take too much imagination to realize the
difficulty of
>   controlling toneality. Oh yes- I have my digital fluid only in the
black
>   cartridge. Image color is determined by color of the ceramic
particals.
>   Final image is monochrome.
> 
>   I wish to improve the low contrast details- especially in the
lighter tones
>   and keep details and contrast in the darkest areas. I am using a 4
pico
>   liter -all the same size dot printer and only a one nozzle
pattern. If I
>   could use a two nozzle output and control each pattern, it should
allow
>   better control of the dot patterns. I visualize smoother and
better edges of
>   contrasty areas and perhaps more detail in lighter tones. This is
where QTR
>   could help me examine and test possibilites were I able to program
my test
>   curves. My trials with QTR curve creations have not been
successful as I am
>   not knowledgable in digital programming. I have asked if there is
a QTR
>   class or some one who would mentor me I will be more than willing
to send
>   you examples of decals and a ceramic tile if this will help you
guide me to
>   better understand QTR curve creation. Many thanks for taking time
to read
>   and perhaps consider my request.
> 
>   Harry L Burnett Jr.

> 
>  Again I am not being understood completly.  I have only one digital
fluid that will jet reasonably well.  It cannot be diluted or thinned.
 So I can could use this same fluid one or more positions and control
each position independantly of others. When using using a "normal" set
of curves, dot gain for three or four positions printing
simultaneously adds up and  is imense.  This indicates I must generate
a set of very low contrast curves that together will yield normal
results.  This is at the heart of my request for help.  How can I use
QTR to create these low contrast curves?  Thanks again. Harry L Burnett Jr
> 


Hello Harry. If you cannot change your ink density (by that I mean use
 less pigment in your home made mix with the fluid.), then it would
seem that changing the ink limits is the only means of control you
have. You could use 2 or 3 jets with the same fluid and density and
reduce the overall default ink limit to 1/2 to 1/3 of normal.That
would keep the total amount of ink the same while giving hopefully
smoother results. Note that you can just keep reducing the ink limit
with even the one jet method until you are seeing less of a problem.
There is likely nothing you can do about the dot gain. It is what it
is. You might try using a curve already in QTR such as one of the 3MK
curves and just modify it a bit. You should not have to muck about
with trying low contrast images etc to get results. Eric was not
misleading you.

Regards
Duane