Mentat:  Thanks; Yes, that is the kind of thing I am thinking of.  A series of techniques that allow an artist to produce sketches that appear to be pencil, charcoal, etc.  These techniques could be made easier to use with a script that assists in the selection of brushes, etc.  Concept sketches could be created within ZBrush for ZBrush projects.
I started out trying to create a pencil sketch look, but my first drawing has more of a charcoal or conte crayon appearance.
Mahlikus & Fouad: Thanks.
Here is a more charcoal-like sketch.  The texture created by the stencil is much ‘finer’ in this picture:
   [img]http://www2.zbrushcentral.com/zbc_uploads/user_image-1035565432tsh.jpg[/img]          
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With material set to Noise Bump (51), (EDIT: default white works pretty good as well.) and color at a mid grey, create a plane that fills the layer.
 
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Use the MRGB grabber to get this ‘texture’.
 
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There may be a better way to create the alpha with a different process, but for now I just use the Create Alpha button in the texture panel.  This creates a better alpha than the MRGB does by itself… (EDIT) …in this particular example. (/EDIT)
 
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Clear the layer and fill with the desired paper color.
 
(EDIT)
4b.  The texture selected earlier should be deselected.
4c.  Bake the layer.
(/EDIT)
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Turn on the stencil.
 
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Before the new stencil is created, adjust Blur in the Alpha palette to suit.  Negative blur can have a beneficial effect on the original texture.
 
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Press the Make Stencil button in the Alpha Palette, and select the Actual button.  The ‘paper texture’ stencil should fill the layer.  You may want to invert it for a different effect.
 
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Deselect the Show button in the Stencil palette to hide the stencil overlay.
 
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Select the desired drawing Alpha.  For the above picture, I used Brush 03.
 
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Select the Simple Brush tool.
 
(EDIT)
11.  Select the Freehand Stroke.
(/EDIT)
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The Material I used was the flat shader.
 
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Draw sizes of 3 to 24 were used the most in the picture above, but large areas can be quickly shaded with much larger brush sizes.
 
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Set the Draw palette to RGB only, and ZAdd and ZSub OFF.
 
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I use an RGB intensity of about 10, more or less, for both shading and highlights.  However, there is one time to switch to RGB intensity of 90-100, and that is when erasing.  Select your background color more quickly by moving your cursor to an open area and pressing ‘C’.  Then set intensity to 90-100.  Now you can ‘erase’ back to the base paper color.  Low RGB intensities while erasing can give you an ‘incompletely erased’ look, which may be desirable sometimes.
 
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Only 3 color settings were used in the drawing above:  the ‘paper’ color, solid black, and solid white.
 
NOTE: The above was done with a plain mouse.  The previous two drawings above where done with a pen and tablet, which gives better control in certain ways, but the mouse can still work very well with this technique, I think.
(EDIT)
I have included a setup script that also includes a short demonstration that can also be played as an option after the setup is complete.  I hope to add notes throughout the script soon.
SketchSetup.zip
Here is a 1.23b version:
SketchSetup123b.zip
Unfortunately, the demo part only partially works, and I will have to do something in 1.23b and add that onto this script.
(/EDIT)