[Amps] fiberglas tape

[gdaught6 at stanford.edu]

Hi,

I've often read "wind the toroid core with fiberglas tape..."  What 
the heck is fiberglas tape?  

There is fiberglass tape for patching drywall, and for covering seams 
when building a boat, and other stuff that I can find at my local 
hardware places.  But none of this tape seems appropriate for winding 
around a toroid before the turns of copper go on.

What is the right stuff, and where does one get it?

73,

George T. Daughters, K6GT