Digital BW, The Print

Evan,

RGB mode provides more options for photo manipulation in PS, more 
filters, smaller file size, etc.  Also, conversion to CMYK generally 
reduces the gamut depending on which flavor of CMYK you choose.  
Probably not as big a deal for monochrome images, but picking the 
wrong CMYK in a color managed workflow could needlessly reduce 
dynamic range (you generally wouldn't want to convert to US Web 
Uncoated unless you want a lackluster inkjet print).  Most inkjet 
printers, even though they print with CMYK inks, expect RGB data 
unless you are using a CMYK RIP.  So, if you send CMYK data, the 
driver converts back to RGB so it can decide how to convert back to 
CMYK again.  Each of these conversions comes at a price.  I'm not 
sure how programs like QTR and IJC/OPM process CMYK data.

I like RGB partly because it is gray balanced, R=G=B.  If you have 
the tools and software to create your own profiles, ideally you would 
want R=G=B to display accurately and print dead neutral on paper, and 
this can be measured with a spectrophotometer.  If you achieve this, 
then you have more control and predicitability in your work.  

That being said, if you find you get better results with CMYK and 
find it more intuitive, use it.  

Lou

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "evanj1969" 
<evanj69@b...> wrote:
> 
>  but if i'm actually printing with gray inks, or cool/warm grays, 
not 
> color inks,  what good does having equal values of R.G.B do me? it 
> doesn't mean my print will be neutral, only my photo in photoshop.
> 
>  does that make sense? after aplying an RGB curve to get the (gray) 
> inks to "print" properly, the image is such a rainbow, the R=G=B -> 
> neutral grey doesn't apply.
> 
>  or is there something i'm missing in you previous post?
>  maybe i'm unsure of what you mean.
> 
> > >does RGB have an advantage over CMYK (excluding file size)?
> > 
> > R=G=B -> neutral grey
> > C=M=Y=K -> ???
> > 
> > Martin
> > --