[cups] Print Black-and-White with black only

[Rolf-Werner Eilert]

Am 20.12.18 um 11:06 schrieb Johannes Meixner:
> 
> Hello,
> 
> On Dec 19 17:58 Rolf-Werner Eilert wrote (excerpt):
>> what I meant was an additional option that forces
>> black "ink" only for the black-and-white parts of the page.
> 
> if there is no such option in the particular PPD for your
> particular printer model, you may have a look at the section
> "Printer drivers: Make the printer print" in
> https://en.opensuse.org/Concepts_printing
> that reads (excerpt):
> -------------------------------------------------------------
> using a monochrome ... driver is probably the best way
> to enforce fast monochrome-only printing
> -------------------------------------------------------------
> 
> I.e. you may set up a second separated print queue with
> a PPD for a monochrome-only driver (provided such a driver
> is available for your particular printer model).
> 
> FYI:
> 
> I use this method at home for my PostScript+PCL color laser
> printer where I have a second print queue with the good old
> traditional PCL5e Ghostscript driver 'ljet4' for fast black-only
> printing - regarding PostScript versus PCL and 'ljet4' see
> https://en.opensuse.org/SDB:Purchasing_a_Printer_and_Compatibility
> 
> In business environments two print queues for one printer
> can lead to some confusion for the users (one queue looks
> idle but no printout hapens via this queue because actually
> the printer is busy with a huge printout from the other queue).
> 
> 
> Kind Regards
> Johannes Meixner

This is a good idea in case of monochrome-only, but in my case it's gray 
boxes and grayscale pictures on pages with black and colored text, 
colored boxes, color pictures etc.

When I print the PDFs from Linux, text appears  much sharper than from 
Windows, so generally Cups is doing a good job, but gray boxes appear 
with a slight pinkish hue, and grayscale pictures as well, so I can see 
that colors are not completely switched off. Printing from Windows does 
not show this. All special features are on "Printer default", however, 
so I must guess: it might be "Printing Text and Pictures".

As I use the same PPD for both OSs, I thought this option could be 
reached somehow from Cups, too.

This option is there, and it will be my next trial.

Regards
Rolf