Darkness stuck at 0 when printing from Linux

[nickrbogdanov]

On my print server I am using lprint with a Zebra 2844 in EPL2 mode. On my client I am running Ubuntu 22.04 with CUPS, and trying to print a 4x6 label from evince. The server is running the master branch of lprint and pappl, compiled from source.

I observed that the printed labels were very light, so I added a debug print in lprint_epl2_rstartpage() which told me that options->print_darkness is 0. This causes a D0 command to be sent to the printer. I was not able to figure how how to override this darkness setting through the UI.

I do not see a darkness option anywhere in the Linux print dialog. I see a "quality" option which doesn't seem to do anything (Draft/Normal/High). I do see a printer-darkness-configured option in .lprint.conf which does not seem to have any effect on this setting. I tried fixing it at 100, to no avail.

My current workaround is to modify the lprint_epl2_rstartpage() code to always send D15 but this isn't a great solution. I would prefer to have a way to set this to a fixed value server-side that is appropriate for the media/hardware in use (e.g. an old printer with a "weak" print head), so that every client doesn't have to manually adjust this parameter.

[michaelrsweet]

Hmm, the defaults (set either from the command-line or web interface) should be applied since it is unlikely the CUPS client is specifying the print-darkness attribute... Can you attach a copy of your .lprint.conf file? (you'll probably have to rename it with a .txt extension...)

[michaelrsweet]

I think I found the problem:

[master 65fa807] Use composite darkness value (Issue #104)