There are many products available that will do the job but MDF (medium density fiberboard) seems to be the most popular. This product is cardboard-like in that it can be torn or scuffed if you are not careful. For instance, when you are cutting it and get to the end of the cut. If both sides of the cut are not well supported, the cut can tear the rest of the way under the weight of the product. Strange stuff ! I am not sure exactly how it is made but it looks like powder that has been glued together and pressed into the desired size, 4x8 sheets for example. Which brings up another point. This stuff actually measures 49 inches wide, which can be a pain in the backside if you are not careful.

I sold and shipped my 2nd wood track to Arizona. The material being 49 inches wide presented quite a challenge to make a crate out of 4x8 plywood for shipping. The 4x8 plywood actually measures 48 inches.