On TV recently saw use of a fibreglass mesh tape that is slightly sticky
and
is applied to the joint BEFORE any plastering mud is used.
With other tapes AFIK usually some mud is applied to the joint and the,
typically perforated paper, tape is stuck to that initial application and
'smoothed' into it with the trowel.
Further applications of mud (plaster), as many as two or three more,
finish
the joint. Metal is best for 'outside' plaster corners. Terry.

I believe the mesh tape you saw is the scrimtape used almost exclusively in
the modern building trade for years now.

Glen