Where can I get Elastic Canvas?

[Stephen]

Hi,
  I'm giving an estimate for some chairs and a loveseat in a college cafeteria back room. They furniture has a kind of (for lack of knowing what else to call it) an elastic canvas that is used to support the loose cushions. I realize that I could use elastic webbing in place of it (which I may have to), but am looking first to see if anyone knows where I can get this product. Anyone know where to get this elastic canvas and what it's real name is? Here is a picture of it in use.

(Click to enlarge picture)
Best Wishes,
Stephen

[sofadoc]

Take a look at this stuff:
http://www.dymetrol.eu/english/operating/public_transport.htm