Thanks, Russell and Jim, for trying to help me out here.  The cardboard
I now use is 1 mm thick (about 0.039 inch), but some other types of
cardboard I use were about 0.7 mm thick.

Inkjet printers are not very good for this type of job, I guess, since
the ink doesn't attach itself very well to the slippery surface of the
cardboard.  Plotters would do better, I guess, but are they capable of
handling such thick material?  I found some really cheap second-hand
plotters on auction sites in Belgium, so I might give it a try, unless
someone can assure me that it won't work.

The quality of the printing needn't be excellent, but the precision
on the other hand...?  But I don't think this will be a problem with
a plotter, no?  And what about the interface?  Do these plotters have
standard printer port (LPT) cables?

Many thanks for helping me!

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