"Larry Spitz" wrote in message
...
[...] It is three plies.
The outer plies are about 0.2 or 0.3mm, so the inner ply is about 0.6mm.
[...]
I would like to know what the plywood is called and where to obtain it.

I bought a quantity of it some years ago. It was know as Aircraft Ply and
was very thin flexible WBP birch plywood.
That's in the uk.

Tim w