It's a geotextile. You can find it at any place that carries silt fence, erosion control material etc. We use it to wrap columns when blasting a building or other structure.

I'm cheap.

In the past, I have made my own from either trevira or some other type of heavy spun fabric. Its flexible and will protect from dust scratches but its not going to stop a direct debris hit. I've had my share of those.