I think it is not the tube material, it is the goop, the cement, which has been denatured so dopers don't sniff it. There's no toululene or whatever the vulcanizing solvent was. So it does'nt stick. Isn't progress great ? I have 2 or 3 tubes of "really good stuff" left over and guard them jealously.
Tube quality has gone to hell also - I've had several tubes come out of the box FLAT! Even the good Michelin / Contis are not what they used to be.
Mark Petry
Bainbridge Island, WA