Digital BW, The Print

Paul,

Thanks for that. It'll take me a while to understand what you're talking
about but I'm sure I'll get there in the end :)

BTW, I've lost my magenta cast now.

Thanks,
Colin.

> ----- Original Message -----
> From: "Paul Roark" ...
> >
> >> If you want to start modifying the curves, print the 21-step test file
to
> >> see exactly where the problems are.  Then open the curve in question
and
> >> move the points where the problem is in the appropriate direction.  I
> always
> >> use the 0-256 (8-bit) scale, instead of the 0-100% ink scale, in order
to
> >> have better control.  The cyan curve is the one that gives the best
> control
> >> in the midtones.  Move the point about 3 units for each 1% that the
> 21-step
> >> test print is off by.
>
> Colin wrote,
>
> >Which way should one move it?
>
> When you are in the 0-255 mode curves (graph) dialogue box (mode switched
by
> the arrows in the horizontal axis), pure black is represented by (0,0),
> which is at the bottom left of the graph.  White is the upper right corner
> (255,255).
>
> So, if you want to darken a patch on the 21-step test file print, go to
that
> point on, for example, the red (cyan ink) graph and move it down.  You
have
> to think in complimentary colors here.  The Red curve controls the cyan
ink,
> which is your main midtone ink.  Moving the point down makes the image
> darker by adding more ink.
>
> To get to the point on the graph that is of interest, you can use your
> mouse, but be careful not to move the point when you click on it.  A safer
> method is to use the control-tab key combination to move to the right, or
> the control-shift-tab to move to the left along the graph.
>
> > Also, the curves on my system are split into RGB not CMYK.
>
> I found the CMYK controls do not give as good a control as the RGB
controls.
> Someone said that the Epson driver converts CMYK to RGB to send it to the
> printer, and in that translation, you appear to lose good control of the
> inks.
>
> So, the black ink is controlled only indirectly by the combination of the
> RGB curves.  The driver makes the decision to start bleeding in black ink,
> and ultimately pulling out the "color" inks, by looking at where the RGB
> inks are.  As all 3 RGB inks approach the black end of the graph, the
system
> starts to substitute black for color inks.  Because of this, smaller moves
> of the points on the RGB inks starts to have more dramatic density effects
> on the print as you approach the (0,0) pure black point.  In the darkest
> quadrant, you'll get about 1% density change per 1 unit move of the Red
> (cyan) ink point.
>
> Hope this helps you fine tune your system.
>
> Paul
> http://www.PaulRoark.com