Can I bring plywood into Mexico?

Oh man don't go there! You'll have to get a permit from PROFEPA, a huge beauracracy.
We shipped some stuff from our home NOB that included an empty picture frame. It was classified as wood and it took months and much $ along with help from Spencer's office to finally get it. Yikes! YMMV

All wood, including and especially crating entering Mexico, MUST have the ISPM-15 stamp certifying that it has been heat treated.

Lacking stamp, I doubt that it will ever cross the border!

This applies to most countries "nowadays" Kind of late in many cases!

gm

Is this a special plywood? I found lots of GIS of various thickness in Home Depot in Guadalajara and in Colima.

I think he means "Good 1 Side".

There is a lumber yard in Chapala, opposite Soriana on the highway lateral. They may have what you want.

And they cut to order at no charge.