PVC stripe suppiler..
 

I used to race at onroad club, they have really really strong PVC stripe as corner markers... i think they are made of polypropolene. So i emailed to old club, and asked them.

I fished out the contact details from other club. it may be use for you.

the email said

"It came from Armadillo Supplies near Warwick - http://www.192.com/atoz/business/warwic ... 1802/comp/

It came in 8ftx6ft sheets and I think its polypropolene. It was available in 3mm and 2mm thicknesses, most of what we use is 3mm. They also cut it into the strips for us

It must be over 10 years ago since we got our stuff so what they do now you will have to find out"

Hope it's useful to you.... I am willing to contribute toward to it if it wasnt too expenisve.