And now for something not-completely different:

I just committed support to Gutenprint for a couple of Magicard ID card
printers, the Rio 2E and Tango 2E. It's likely other models will work
okay too, but that would require someone willing to test things a bit.
Most features of the printer are supported; overcoat including the
so-called holokote, holopatch, and overcoat holes; fine-tuning card
alignment and even mag-stripe encoding.
Notably missing are duplexing (My Tango2E's duplexer is busted),
smartcard encoding, holokote holes, and non-CMYKO ribbon support -- eg
monochrome-only and CMYKOKO ribbons. There's also no sane way to query
and report the printer status, but that's something I intend to keep
poking at.
Output-wise, the black layer is slightly misaligned with the color
layers, and there also appears to be a problem with the gamma
correction. The former is probably a matter of some fancy footwork, but
the latter is likely due to the dodgy print head on my unit that is also
responsible for that mangled stripe down one side. One can't complain
too much when one wins a lowball eBay auction for an "as-is, parts-only"
printer!
So, if there are other folks out there who want to be able to create ID
badges using on Linux and entirely Free Software, it's now not only
possible, but will yield high quality results. Extending this support
to other Magicard models should be straightforward, but I've pretty much
done all I can with what I have access to.
So, I'm putting the Magicard models aside for the time being, and, time
permitting, will turn my attention to a well-used but otherwise fully
functional Zebra P120i printer I recently got for a song on eBay. This
one came with a full set of programmer's documentation, so I won't have
to spend time reverse engineering anything (you hear that, Magicard?
Publishing documentation leads to good things happening, and can open up
entirely new markets for you. Not everyone wants to run their systems
on x86+Windows!)
Beyond Magicard and Zebra, there are three other major players in the ID
card space; Evolis (full documentation, woo!), Fargo (no documentation)
and DataCard (some documentation). I probably won't bother with any of
these unless someone steps up with some hardware; my personal needs will
be well met with what I have now, and my time for fun hacking is a lot
more limited these days.
Happy printing, folks!
Update 2018/02/21: The gamma curve problems are resolved, but the black registration issue remains.