Digital BW, The Print

Paul,

Just to be clear when you describe the following issue - that's using the
Epson driver - correct ? Txs Mike

>>There is at least one possibly open issue with respect to the recommended
Eboni-6 ratios in K3 printers. With the original Carb-6 mix, the C-position
was 33%, then the M/LK was 16.5%. If no PS curve was used to partition the
inks, there was some posterization in the deep shadows. The high gray
substitution of the K3 printers with an input of an R=G=B grayscale file
caused the relatively lighter, original Carb-6 16% LK to be too light
relative to the darker 33% C-position ink. I believe this is not a problem
with the standard Eboni/Carbon-6 setup (using 18% for LK and 30% for C), but
it's something to keep an eye on. If it is a problem, then the LK needs to
be the 30% ink, not the 18% ink

On 10 March 2011 17:05, Paul <roark.paul@...> wrote:

>
>
> "Gerd" <lichtwert@...> wrote:
> >
> > ...
>
> > what are the specific/explicit dilutions for a carbon-6 mixing for an
> eight-color printer like the R2880? I would appreciate a detailed listing
> for each color related to volume.
>
> I have never actually set up a 2880. Even with my 7800 I have non-Eboni
> inks in 3 positions. So, the "perfect" setup for an 8-ink printer involves
> some uncertainty. However, start with what I recommend in the PDFs on the
> subject.
>
> Michael King <drmrking@...> wrote:
> >
> > ...
>
> > If you are making your own profile doesn't matter which
> > dilution goes in which channel.
>
> This is true if one makes QuadToneRip profiles. This is what I use to print
> with my 7800.
>
> However, I most often like to set up a printer with an ink arrangement that
> is compatible with the Epson driver. I think this lowers the entry barriers
> for new users. If they can load the inkset, hit the Print button in PS and
> get an OK print, the positive feedback avoids a lot of headaches (both for
> them and me).
>
> So, to get down the learning curve with the least amount of pain, I
> recommend new people start with an inkset that is compatible with the Epson
> driver, then learn simple linearization so that QTR's Create ICC-RGB can be
> used to make ICCs, and finally, learn the full QTR rip approach, which
> allows one freedom from the Epson driver constraints.
>
> Back to step one -- the Epson driver compatible Eboni-6 arrangement for an
> Epson k3 class printer: page 2 of
> http://www.paulroark.com/BW-Info/Eboni-6.pdf has the recommended setup.
>
> For Carbon-6 I recommend the same mixing ratios as for Eboni-6. See
> http://www.paulroark.com/BW-Info/Carbon-6.pdf
>
> Note that I initially used a different mixing ratio for Carbon-6 to
> facilitate mixing with no scales. This ran into several problems. Stick to
> the 100, 30, 18, 9, 6, 2% standard Eboni/Carbon-6 ratios. Once the base is
> mixed the specific gravities are close enough to use the same ratios for
> both volume and weight mixing.
>
> For the base, the only ingredient you need to adjust for is the glycerol --
> heavy at a specific gravity of about 1.26. So, the volume would be the
> weight percentage divided by this, with water being the remainder -- taking
> up the amount of the difference.
>
> There is at least one possibly open issue with respect to the recommended
> Eboni-6 ratios in K3 printers. With the original Carb-6 mix, the C-position
> was 33%, then the M/LK was 16.5%. If no PS curve was used to partition the
> inks, there was some posterization in the deep shadows. The high gray
> substitution of the K3 printers with an input of an R=G=B grayscale file
> caused the relatively lighter, original Carb-6 16% LK to be too light
> relative to the darker 33% C-position ink. I believe this is not a problem
> with the standard Eboni/Carbon-6 setup (using 18% for LK and 30% for C), but
> it's something to keep an eye on. If it is a problem, then the LK needs to
> be the 30% ink, not the 18% ink.
>
> Hope this helps.
>
> Paul
> www.PaulRoark.com
>
>  
>


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