Restricting use of a colour printer to black-and-white

[Helge Blischke]

John A.  Murdie wrote:

> I'm wondering if and how I might use CUPS to restrict the use of a colour
> printer for certain users so that they can print only in black-and-white.
> The print dialogue boxes of certain operating systems and/or application
> programmes have a 'Black-and-white only' tick box, but that's leaving the
> authority to the user.
> 
> The motivation here is to reduce the number of printers in a space by
> replacing two printers - a black-and-white-only printer and a colour
> printer - with a single printer - a colour printer which prints cheaply in
> black-and-white - and yet to prevent some users from using the relatively
> expensive colour printing.
> 
> Is there a means in CUPS of, first, configuring the filters so that they
> force full-colour jobs to print in black-and-white only and, second,
> having a virtual printer for an existing printer which always does such
> forcing? I don't recall reading about any such explicit features.
> 
> John A. Murdie

It depends on what printer you are using.
If the printer speaks PostScript natively, you could set up a second CUPS
queue pointing to the same physical printer for b/w-only printing and edit
this queue's PPD as follows:

Insert the following snippet near the PPD's section denoting the device
capabilities (like printer memory etc.):
---snip---
*JobPatchFile 1 : "% force printer to b/w only
<</ProcessColorModel /DeviceGray>>setpagedevice
"
*End
---snip---

After editing, restart CPS and print a CUPS test page to this
queue.If the color wheel on the printed test page *does* only
contain gray segments, this hack works; otherwise you need to
look for another workaround.

Helge