Sand back any varnish or paint on a small area of the paneling, if you can. This lets you see whether the material below has a pattern on its surface.
Check out the pattern on the surface of the paneling. If the wood isn't painted, you'll be able to identify a grain. Round, black knots and thin veins running across the paneling are characteristic of pine, for example. Wood panels have a pattern that runs across the surface.
Touch the panel. Stroke it gently to feel what type of texture the paneling has. Vinyl or plastic paneling has a glossy, shiny surface that's silky to touch. Wood may well be smooth, but it will have a more rough, organic feel.
Smell the paneling. It may sound strange, but often you can smell a natural odor emitted from wood. A synthetic material doesn't have a strong of the outdoor; it smells more like chemicals and plastic.
Identify whether the paneling is fitted with tongue and groove to the wall. Tongue and groove is typical of wood paneling. It consists of a series of wooden planks slotted together. There's a slight ridge or break between each plank. This is where the planks are fitted together.
Knock on the paneling with your knuckles. Listen to the sound. If the paneling is wood, you'll hear a light, echo-ey sound. A dull thud will be emitted from materials such as medium-density fiberboard or stone.
Assess the formation of the paneling. Stand back and look at the paneling in its entirety. Wooden paneling is often put up in a series of squares with a sunken area in the middle for decoration, trimmed with an ornamental border, or clad across a wall symmetrically. Check to see whether you can notice any of these patterns on the paneling.