Source for Way Cover material

I'm looking for a source to purchase way cover
material. Often this is a cloth impregnated neoprene.
Neoprene comes in many forms, however, and I don't know
how to spec it. It functions within everything from
wetsuits (obviously very porous) to mud flaps.

Local hardware stores sell the stuff in about 3/32"
thickness that would be great, but they want a fortune
(sell it by the 1/4 square foot). I need some pieces
that are about 24" x 36" and I would go broke buying it
from them.

Is there any discount source people on the group can
recommend? If such a place exists only in the "walk-in"
world, my geographic location is the Silicon Valley, CA.

This is for a Hurco CNC milling machine.... essentially
a Bridgeport knee mill with on a small dose of steroids.

Thanks,
Alan