Backing material on Aussi made embroidered patches?

[Yardstick]

Can anyone with access to examples of any original Australian made embroidered patches tell me what the black backing typically used was made from. Looking at images it appears to be some form of textured paper. Even thought it appears to be woven, examples with a lot of wear seem to show the backing torn like paper rather than frayed like fabric.

I’d love to finish my Aussi style patches off with the correct backing but have never been able to work out what they used.

Would be very grateful to anyone that could throw some light on the mystery.

 

[ausreenactor]

Don't have anything other than raw backed shoulder insignia.