Sawdust

Sawdust is a by-product of cutting, grinding, sanding, or otherwise pulverizing wood with a saw or other tool.

Physical appearance
It is composed of fine particles of wood.

Season one
The gang found sawdust in the Snow Ghost's footprints, leading to a sawmill.

Appearances

 * Scooby-Doo, Where Are You!
 * 117. That's Snow Ghost