Digital BW, The Print

> From: Clayton Jones [mailto:cj@...]
>
> I'm not sure what you mean by "CMYK combinations" when I'm printing BO
> from only the black cart.  Doesn't that mean combinations of various
> inks?

Yes, a later message from you clarified that you were printing BO.

> 1) Why did the S-curve, which didn't move the zero anchor point and
> theoretically didn't change any already zero pixels, make the printer
> put down more ink in a patch that was already solid zero pixels?

Have you tested it with some solid patches, so that you _know_ you're seeing
this effect in a 0,0,0 area, rather than on something nearby which isn't
quite 0,0,0?

> 3) Why does adding more ink to an already 100% covered area of pure
> black increase Dmax?  Does a lesser amount of ink sink in deep and
> leave less on the surface, and a greater amount "fills it up" so to
> speak?

I suppose any real-world black ink passes some light, so laying it down
thicker will increase the Dmax a tad.

> 5) Here's the biggie: The paper is capable of much better Dmax if you
> give it more ink.  I found that I can give it more ink with the curve
> (for whatever mysterious reason), but it ruined the pic because the
> rest of the image was too contrasty.  How can I make the printer give
> it more ink in zero RGB zones without changing the contrast?

You should test this on a 21-step wedge, and on a gradient, to see if there
is any inversion in the scale. I'd be curious to hear your results.

--

Ciao,                   Paul D. DeRocco
Paul                    mailto:pderocco@...