Plywood.
One of my favorite tracks on anything is YYZ off of Rush's Moving Pictures. Just after the 2:26 mark there is something that I always equated to the sound of a thunder clap. My Uncle told me the sound was actually created by slamming a piece of plywood into a wooden stool and sure enough plywood is listed in the liner notes of the album.
In an interview for the Rush Backstage Club Newsletter, December 1985 Neil Peart is asked
Q. How do you play plywood?
A. Well you wear gloves so as not to get splinters, you take a piece of 1/4" plywood, and smack it down hard on the top of a wooden stool. Very demanding, technically? took years of practice.
So my answer is plywood. Or technically plywood & wooden stool, but plywood is the only one that ended up in the liner notes. Justice for wooden stool.