Hi to all!  About plotters: I've noticed indeed that it will require
some extra software to use a plotter as a cardboard printing machine
with the Midiboek program or, e.g., MS-Word -- which is understandable,
of course.  But this software is not really cheap, so perhaps a plotter
will indeed be too expensive.

About inkjet: the main problem is still that the paper path is often
'curved', so it won't handle folded organ cardboard.  I don't know what
the weight of the cardboard is, but it's way too heavy compared to the
weight that inkjet printers allow.  1 mm thickness is also way too
thick for a normal inkjet printer.  I know, inkjet printers do print
on glossy paper, etc., but those papers have a special coating that
takes up the ink quite well, a coating that is not to be found on the
organ cardboard.  Also, inkjet cartridges are not very cheap, and if
you want to print a lot of cardboard, that would cost quite a lot,
I guess.

Of course, it's just a hobby, and if I had to choose between spending
1000$ on good arrangements and cardboard or 1000$ on a printing
installation, well...

Anyway: many, many thanks to all who answered my question!

Best wishes,
Bjorn Isebaert
Belgium
Bjrn.Isebaert@skynet.be.geentroep (remove .geentroep to reply)