Cynthia Moore wrote:
I have a very old Herman Miller Aeron chair. The right arm rest has
cracked and the cover is tearing. I've tried 2-3 kinds of tape to repair
it, but none work well.

A couple of types of glass tape work well while they last, but the
constant stretching eventually causes them to start to separate.

Electrical tape doesn't have the splitting problem, probably because
it's stretchy itself. But it doesn't stay in place.

The arm rest is removable so I can wrap the tape completely around the
top to the underneath part where it is held in place with a couple of
heavy screws.

Any suggestions for a different kind if tape? I would prefer black as
that's the color of the arm rest.

Thanks, guys ;-)

Maybe an auto upholstery shop would be an answer. There's a site
here that might help: https://www.ifixit.com/
There is an electrical tape for watertight connections that is really
flexible. It's so sticky that it comes with plastic wound in with it to
help it separate for application. It isn't all that tough though.