Martin Eastburn wrote in news:IiEOy.11705$__
:

Plywood is simply veneer over another surface.

Well, no, not really. To be plywood the layers have to have
the grain going crosswise (or, rarely, at 45 degree angles).
That is what gives plywood it's dimensional stability.

Granted there are modern day composites used for "plywood"
cores that don't have grain, but those didn't exist when the
first manufacturers started making plywood.

John