[GreenKeys] What ink for ink cart.

[Jim Haynes]

Back in the 1960s the preferred stuff came from National Cash Register,
was available in black and purple.  There was a fixture made and sold
for reinking ribbons, consisting of two pegs and two ribbon spools with
one side taken off, so you could apply the ink from a squeeze tube to
the ribbon and wait for it to soak in and roll it back and forth to
distribute it evenly.  I don't know if NCR still uses ink anymore - seems
like all the cash register tapes these days are thermal printed rather
than impact printed.

The makers of numbering machines (Bates and others) always cautioned 
against using stamp pad ink, insisted you use their formulation.

Back when dot-matrix printer were in full bloom I was told that they
required an ink with some lubricating properties, and that it was sold
in places like Computer Shopper, but I never bought any.