When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

Your requirements of this or that or orientation doesn't hold water.

Apple ply is not the same as a fur or pine ply.

Having a solid core is strong. The ply's on the outside is dressing.

You are making commercial product and saying PLY has requirements to be
ply.

I've used Plywood since 51 or 52. They made it in the back shop of the
hardware store. They bought vernier sheets and made their own using
their waterproof glue for all uses.

Martin


On 4/11/2016 7:50 AM, John McCoy wrote:
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