[cups] Printing 2 copies on a double sided printer

[Gene Heskett]

On Thursday 01 October 2020 03:59:06 Johannes Meixner wrote:

> Hello,
>
> only FYI some background information about what is called "copies":
>
> There is no such thing as "printing copies".
>
> There are several essentially different ways how one could get
> the same content printed multiple times (vaguely called "copies"):
>
> E.g. when printing 3 "copies" it can be done as follows:
>
> # lp -d queue -n 3 file_to_print
>
> (one print job where number of copies is only a print job parameter
>   and then it depends on various conditions what exact behaviour
>   that print job parameter results - a filter may produce multiple
>   pages or the printer may do it or both so that one gets 9 pages)
>
> versus
>
> # lp -d queue file_to_print file_to_print file_to_print
>
> (one print job with the content file as many times as number of copies
>   which I consider as the most reliably way how one could get the same
>   content printed multiple times for the price of more needed
> resources cf. RFC 1925 item 7a)
>
> versus
>
> # lp -d queue file_to_print
> # lp -d queue file_to_print
> # lp -d queue file_to_print
>
> (as many separated print jobs as as number of copies where it can
> happen that other user's print jobs get in between so that the jobs
> from the other users appear in between in the whole printout plus
> maximum needed resources how to get the same content printed multiple
> times)
>
> Those are the three essentially different ways how one could get
> the same content printed multiple times (vaguely called "copies")
> where each way could result different unexpected behaviour.
>
> When the number of "copies" is only a print job parameter
> one can get the same content printed N or N^2 or N^3 ... times
> depending on how often that print job parameter is evaluated.
>
> When one gets N^2 "copies" only with some kind of printer models
> the reason is likely that first a CUPS filter makes copies
> and then the printer itself also makes copies.
>
> Inspect the PPD file of the printer /etc/cups/ppd/<queue>.ppd
> if there are some kind of copies options therein and if yes
> it may help to play around with that options in the PPD file.
>
> Another issue related to "copies" is "collated copies":
>
> Collated copies means that when printing more than one copy
> of a multi-page document it will print all pages of each copy
> before printing the next copy.
>
> So the printed page numbers for printing 2 collated copies
> of a 3 pages document are
> 1 2 3 1 2 3
> versus printing 2 non collated copies of a 3 pages document
> results the following printed page numbers
> 1 1 2 2 3 3
>
> In particular cheap/weak printers that provide a built-in
> copies functionality may support only non collated copies
> (e.g. because of too little built-in memory to keep the whole
> document to print it as a whole multiple times - but sufficient
> built-in memory to print a single page multiple times).
>
> Now put "duplex printing" on top of that and imagine the possible
> outcomes when printing 2 collated copies of a 3 pages document
> with duplex printing enabled.
>
> One would expect to get this printout
> 1 and 2 on front side and back side of the first sheet of paper
> 3 on front side of the second sheet of paper
> 1 and 2 on front side and back side of the third sheet of paper
> 3 on front side of the fourth sheet of paper
>
Which is a good description of what we are getting, imagine the hilarity 
and blue air when we want 3 copies of a document 37 pages long. 6 months 
ago it Just Worked. Something has been updated, and now we must wait 
till the printer is done with one copy, and has reset itself to the idle 
state, THEN we can send another copy, wait for that one to finish and 
the printer is idle, THEN send the 3rd copy. THE OP is not the only 
victim here. Hence my cutting in on this thread.

> But one may get that printout
> 1 and 2 on front side and back side of the first sheet of paper
> 3 and 1 on front side and back side of the second sheet of paper
> 2 and 3 on front side and back side of the third sheet of paper
>
or if 2 copies of a 3 pager are requested, two copies of page 1, on both 
sides of sheet 1, page 2 and page 3 on the next sheet, and MAYBE another 
copy of page 2 on one side only of page 3. You wind up throwing it all 
away, and sending the same job 3 times to get 3 copy's...

> Printing non collated copies with duplex printing enabled
> does not make sense because one would get the first page
> printed on front side and back side of the first sheet of paper.

I have had that occur with collated checked. Please better define exactly 
what the "collated" setting is supposed to do in the online Docs.

> On 2020-09-22 17:59, Axel Braun wrote:
> > Am Dienstag, 22. September 2020, 17:26:59 CEST schrieb Helge 
Blischke:
> >> > Am 22.09.2020 um 15:02 schrieb Axel Braun <axel.braun at gmx.de>:
> >> >
> >> > Am Dienstag, 22. September 2020, 10:16:29 CEST schrieb Till 
Kamppeter:
> >> >> On 22/09/2020 10:10, Axel Braun wrote:
> >> >>>> lpadmin -p <printer> -o cupsManualCopies=true
> >> >>>> or
> >> >>>> lpadmin -p <printer> -o default-cupsManualCopies=true
> >> >>>>
> >> >>>> where <printer> is the queue name of the printer in question.
> >> >>>
> >> >>> I tried
> >> >>>
> >> >>> lpadmin -p MFC9340CDW -o default-cupsManualCopies=true
> >> >>>
> >> >>> before printing from Okular, but that did not fix it.....
> >> >>
> >> >> It must be
> >> >>
> >> >> lpadmin -p MFC9340CDW -o cupsManualCopies-default=true
> >> >
> >> > Unfortunately this still give both copies on the same page.....
> >>
> >> What does work in any case is to insert
> >>
> >> *cupsManualCopies: True
> >>
> >> in the printer’s PPD near the line beginning with *ColorDevice: xxx
> >> .
My ppd's, from brother, for an MFC-J6920DW have no such section. cups 
2.2.1, debian stretch uptodate. But they do have 5 sections for trimming 
brightness, contrast and the 3 individual colors in a -20 to +20 range 
and which are totally ignored by cups when tested about a year ago.
> >
> > This hint was mentioned as well in the KDE bug, but did not change
> > the behaviour either.
>
> Kind Regards
> Johannes Meixner

Thank you Johannes.

Cheers, Gene Heskett
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