Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Austin 
Franklin" <darkroom@i...> wrote:

> Understood...but what is there to doing this aside from
> printing using the standard driver and selecting "Black 
> Only" that was being heralded in another post?

Creating the right transfer function is ESSENTIAL, as it is in any 
digital printing practice.   There are many ways of doing this - the 
Curve adjustment tool in Photoshop is one way, creating a Curve 
adjustment layer is another.  Creating custom profiles is also a way 
to shape the transfer function.  One of my new favorites is creating 
a set of custom gradient maps in Photoshop.  I have ones for 
stretching the midtones, brightening the shadows, etc. 

All of these (and there are plenty of others) do the same thing - 
they determine how a particular RGB or grayscale value in the 
original image will be represented to the printer for output.  

Most of us have a test image we use.  Mine consists of a continuous  
0-255 wedge plus additional wedges with calibrated step functions in 
the shadow, midtone, and highlights, plus a sample image of a model 
with smooth slik tones from shadow to specular highlight. 

One of B.O.'s characteristics is that it produces a highly textured 
output (because of the dotting) in certain density ranges.   One of 
the goals of your transfer function is either
A. to place that texturing in parts of the image that are less 
prominent if you don't want to see it  . . . or . . . 
B. emphasize it, if that's why you're using B.O. in the first place.

The resident expert here on B.O. curve adjustment is Clayton Jones 
so he can give you detailed advice, depending on your goals.