In uk.d-i-y, Andy Dingley wrote:

* At least one plywood supplier with decent exterior-grade hardwood ply
gives you boards with (I presume deliberately) different species veneers
on either side.

This is commonplace. They may not be different species, just different
quality grades.

Thanks for confirming it's commonplace - and therefore worth remembering,
rather than just a one-off.

Where did you get your timber from BTW ? Robbins, Avon Plywood or
elsewhere ?

Robbins - seems like decent quality sheet (though the softwood I bought
for the edging was pretty naff - I didn't feel like paying the extra for
their "joinery grade" or whatever), and they're close by home - maybe a mile
and a half away.

Cheers, Stekef