So sorry it took me this long to get back to you. I had to take a sample of my fabric to the guy who installed it so he could tell me the precise name of the material, and it took until today to do that. It's called "stabilization cloth" (possibly stabilizing cloth). 

I guess the other terms I remembered are more generic... It is not "filter fabric", which I believe is one of the terms I used.That is quite different, and not as strong. He did not know the manufacturer name. It's a tightly woven, flat, plastic mesh. It's tough and it keeps the soil below it and lets the rain drain through. I have a few inches of pea gravel over it. Highly recommend - mine is still fine after 12 years.

Claudia & Silhouette 2014 California

https://groups.yahoo.com/neo/groups/echistory8/files/Claudia%20%26%20Silhouette/