Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Louis Dina"
<lou@...> wrote:
>
> David,
> 
> Sorry for bombarding you, but I thought of one more good approach for
> printing 4/C B&W that will maintain neutrality on press.  
> 
> Do a standard RGB to CMYK conversion, using one of the industry
> standard CMYK profiles (US Web Coated SWOP, Euroscale Coated, etc). 
> This will give you a full 4/C conversion with too much color to
> guarantee neutrality on press.
> 
> To solve this, create a new Selective Color adjustment layer.  Set the
> Method to "Absolute" the select "Blacks" from the drop down menu. 
> Nove the Cyan, Magenta, and Yellow Sliders to the left in equal
> amounts to a figure like -40 or -50.  Make sure they are all adjusted
> by the EXACT same percentage.  This will take color inks out of your
> blacks in equal proportions.  With your mouse cursor positioned over
> the darkest black portion of the image, read the "K" value in the Info
> Palette.  If it is currently reading 90K, move the Black slider in
> Selective color to to the right to increase the back ink.  Don't go
> past 100% K, and keep an eye on shadow detail to prevent blocking up.
>  It is probably better to be conservative and keep the K value between
> 93 and 96% or so.  This selective color adjustment will change your
> file so that black ink greatly outweighs color inks throughout for
> neutral blacks.  
> 
> For further refinement, you can even use the "Neutrals" drop down box
> in Selective Color and play with those settings in a similar fashion,
> but you probably won't need it.  This approach will be more like
> creating a custom profile with ProfileMaker or Monaco Profiler, since
> you still will have a little color in the highlights, but a lot more
> black than color.
> 
> Finally, you can tweak the black channel after this adjustment for the
> best shadow detail and tonal range, but leave the CMY channels alone.  
> 
> Lou
>

David,

Trash the above method.  On further experimentation, it's a dog.  The
intial separation to an industry standard CMYK profile (SWOP,
Euroscale, etc) leaves the black plate totally blank in the
highlights, and it's too much fuss trying to get detail back into the
black plate.  Sorry for the wild goose chase.  

The other two methods (Photoshop Custom CMYK with Max GCR and building
a Max GCR profile with high end profiling software) work fine though.  

Tyler makes an excellent point on what can happen to your file once it
is out of your hands.  If the printer does a conversion of your file
to their "standard", they may totally undo all your hard work and give
you a standard separation once again (ie, lots of color in the CMY
plates and a lower black in the K plate).  In an attempt to guard
against that, you can strip your profiles from the files entirely
before submitting them.  However, if your service provider is
determined to do a conversion, they will then assume a profile for the
source space or just use their default color space for CMYK as source
and hose your file.  

Then only solution I know is to deal with a knowledgeable printer who
understands this stuff and communicate clearly that your files NOT be
adjusted or converted.  This way, your numbers will be sent to the
press.  It's a tough game working with printers.  Communication is
paramount, and working with someone who has a clue also helps!  Many
printers don't.  

Lou