QTR-Quadtone RIP

Harry, I'll assume you are responding to me, the Dane not an Englishman ; ) 

 

If you are only using one channel to run your image, you should be able to
get a better transition if you add a dilution to the mix and run it in one
of the other ink slots. I'd even go so far as to say you could use all four.
With QTR, you run an ink limit to get to a controlled out put. If you have
the measuring devices, then you read the before, your substrate, and your
after, the kiln fired ceramic. I'd use big squares like you'll find in the
100 step target in QTR. Print it out after your "image curve" and plot the
points. You are printing an image, and then transferring that to a ceramic
receiver and firing it. 

 

You are looking to get better separation in the highlights, where now you
are currently getting black to white without good transitions?  I haven't
been using the program much lately, but you should be able to make some
curves to show output values with your final reflected readings.  

 

I'd be tempted to run extremely high dilutions with 4 slots rather than
curve the heck out of the image in PS.  

 

 

Eric Neilsen Photography

4101 Commerce Street

Suite 9

Dallas, TX 75226

http://e.neilsen.home.att.net

http://ericneilsenphotography.com

Skype ejprinter

  _____  

From: QuadtoneRIP@yahoogroups.com [mailto:QuadtoneRIP@yahoogroups.com] On
Behalf Of Harry Burnett Jr
Sent: Monday, March 24, 2008 7:41 PM
To: QuadtoneRIP@yahoogroups.com
Subject: [QuadtoneRIP] QTR Help for photoceramic curve?

 

Dear Mr Nelson:

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.

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