Digital BW, The Print

Can someone explain to a relative novice, why it is , in many 
worflows I've read, a grayscale file of a B&W image is converted back 
into RGB before printing? How will the print differ if the grayscale 
file is printed?

It's prob very obvious so no one ever explains it, so I've never seen 
the explanation anyewhere.

Thanks,

Andrew

> From: alnchiem [mailto:andrewlee@...]
>
> Can someone explain to a relative novice, why it is , in many
> worflows I've read, a grayscale file of a B&W image is converted back
> into RGB before printing? How will the print differ if the grayscale
> file is printed?

If you're printing an RGB image with color inks, you can impose a slight
overall tint to the B&W image.

--

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

Andrew,

Are you asking about this in the context of a B&W/"quad" inkset or a color
inkset?

Paul
http://www.PaulRoark.com
_________________________________

-----Original Message-----
From: alnchiem [mailto:andrewlee@...]
Sent: Wednesday, November 12, 2003 9:28 PM
To: DigitalBlackandWhiteThePrint@yahoogroups.com
Subject: [Digital BW] Why back to RGB in B&W workflow?



Can someone explain to a relative novice, why it is , in many
worflows I've read, a grayscale file of a B&W image is converted back
into RGB before printing? How will the print differ if the grayscale
file is printed?

It's prob very obvious so no one ever explains it, so I've never seen
the explanation anyewhere.

Thanks,

Andrew



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I think what it is to which you are referring is the technique to
segment the various grey ink tones to grey shades of the print...

Consider the Epson driver: it creates grey shades by a balanced mixing
of cyan magenta and yellow inks to make grey. Thus the lighter shades
of a print above black will have small dots of CM&Y sprayed out on to
the paper. If the color inks are replaced with three shades of grey,
the Epson driver, if printing a B&W image, will do the same thing. The
result is that the darkest grey will be included in the very light
tones and visible dots will result.

Now a way to use only the light grey in the light areas, medium in
medium and the darkest grey ink in the shadows: If the lightest grey
is in the Yellow position, tell the Epson driver to print levels of
yellow ( 'color' ) and you will use Only the lightest ink for the
shades near white and render the print 'dotless'. Make areas of the
print a nice ugly magenta, and only the medium grey will be applied,
cyan colors in your RGB print (as shown on the monitor) will make the
dark greys.

So, your print must be converted to RGB, then turned in to intensely
colored areas to force the Epson driver to use an appropriate grey ink
for a particular grey level. If adjusted correctly, a segemented
workflow can create a wonderful dot free, fine quality black and white 
print !

Best,
Alex
> Can someone explain to a relative novice, why it is , in many
> worflows I've read, a grayscale file of a B&W image is converted
back

> into RGB before printing? How will the print differ if the grayscale
> file is printed?
>
>
>
> Thanks,
>
> Andrew

Well Paul, I don't recall if the workflows I've read specifically 
relate to prepping an image for quad inks or not, but it seems common 
for people to add this step of converting to RGB before sending to 
print.

Andrew

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Paul Roark" 
<paul.roark@v...> wrote:
> Andrew,
> 
> Are you asking about this in the context of a B&W/"quad" inkset or 
a color

> inkset?
> 
> Paul
> http://www.PaulRoark.com
> _________________________________
> 

>

Alex
thanks for that explanation. That ould mean much more work than just 
converting from grayscale to RGB. Or is there some 'already 
available' adjustment file to segment the greys in an RGB file so 
that the Epson driver knows what to do? Is that the software in a QTR 
or these adjustment curves?
Andrew

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "B. Alex Pettit 
Jr." <a_pettit_jr@y...> wrote:
> I think what it is to which you are referring is the technique to
> segment the various grey ink tones to grey shades of the print...
> 
> Consider the Epson driver: it creates grey shades by a balanced 
mixing
> of cyan magenta and yellow inks to make grey. Thus the lighter 
shades
> of a print above black will have small dots of CM&Y sprayed out on 
to
> the paper. If the color inks are replaced with three shades of grey,
> the Epson driver, if printing a B&W image, will do the same thing. 
The
> result is that the darkest grey will be included in the very light
> tones and visible dots will result.
> 
> Now a way to use only the light grey in the light areas, medium in
> medium and the darkest grey ink in the shadows: If the lightest grey
> is in the Yellow position, tell the Epson driver to print levels of
> yellow ( 'color' ) and you will use Only the lightest ink for the
> shades near white and render the print 'dotless'. Make areas of the
> print a nice ugly magenta, and only the medium grey will be applied,
> cyan colors in your RGB print (as shown on the monitor) will make 
the
> dark greys.
> 
> So, your print must be converted to RGB, then turned in to intensely
> colored areas to force the Epson driver to use an appropriate grey 
ink
> for a particular grey level. If adjusted correctly, a segemented
> workflow can create a wonderful dot free, fine quality black and 
white 

> print !
> 
> Best,
> Alex

You get a better (richer) blacks and a wider tonal range using all colors.  Of course if 
your printer profile isn't good, you can also get a color cast.  I think that the best B&W 
is printed with all colors (assuming not quad tones, etc), but also the hardest.  Some 
will tell you that it can't be done, but they are wrong.

Bill

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "alnchiem" 
<andrewlee@h...> wrote:

> Well Paul, I don't recall if the workflows I've read specifically 
> relate to prepping an image for quad inks or not, but it seems common 
> for people to add this step of converting to RGB before sending to 
> print.
> 
> Andrew
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Paul Roark" 
> <paul.roark@v...> wrote:
> > Andrew,
> > 
> > Are you asking about this in the context of a B&W/"quad" inkset or 
> a color
> > inkset?
> > 
> > Paul
> > http://www.PaulRoark.com
> > _________________________________
> > 
> 
> >

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "alnchiem" 
<andrewlee@h...> wrote:
> Alex
> thanks for that explanation. That ould mean much more work than 
just 
> converting from grayscale to RGB. Or is there some 'already 
> available' adjustment file to segment the greys in an RGB file so 
> that the Epson driver knows what to do? Is that the software in a 
QTR 
> or these adjustment curves?
> Andrew
> 


Andrew -- No real work, it's a simple process.  So long as your 
printer is supported with pre-made curves, you just convert to RGB 
and load the appropriate pre-made curve in an adjustment layer.  The 
image will look funky on-screen but will print beautifully.

Paul R. and others have spent an incredible amount of time developing 
curves for the most commonly used printers.

-- Herb

Is there a reason to load the Roark curves in an adjustment layer 
rather than just applying them directly to the image?  

Steve

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Herbert Sitz" 
<hsitz@n...> wrote:
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "alnchiem" 
> <andrewlee@h...> wrote:
> > Alex
> > thanks for that explanation. That ould mean much more work than 
> just 
> > converting from grayscale to RGB. Or is there some 'already 
> > available' adjustment file to segment the greys in an RGB file so 
> > that the Epson driver knows what to do? Is that the software in a 
> QTR 
> > or these adjustment curves?
> > Andrew
> > 
> 
> 
> Andrew -- No real work, it's a simple process.  So long as your 
> printer is supported with pre-made curves, you just convert to RGB 
> and load the appropriate pre-made curve in an adjustment layer.  
The 
> image will look funky on-screen but will print beautifully.
> 
> Paul R. and others have spent an incredible amount of time 
developing 

> curves for the most commonly used printers.
> 
> -- Herb