My boards were made outta 3/4" Maple with a pointed nose and a kick tailMy board is handmade by 9 ply Baltic birch plywood
It's really flexible, and I prefer that. The flex yields a cooshy ride and helps the wheels bounce over road debris.
Layer ply flex boards weren't invented yet they were all a strong flexible fiberglass made by custom shops
I see were off topic, Oops,