Parafilm

Working in the lab at uni, we use quite a lot of a product called parafilm for sealing up the necks of jars and the tops of test tubes, etc. It's a clear, waxy film sold in 250ft rolls, either 2" or 4" wide, and also 20"x50' rolls. The 2" stuff will stretch out to approximately 20cm.
Anyway, I haven't been able to try it out yet, but I got to thinking that, being airtight and waterproof, this may be useful as an alternative to paint-on sealers for woodturning blanks - the advantage being that it does not penetrate, leaving more usable timber on the periphery.
Only problem is, I have no idea how much it costs.
Might be useful for those who regularly cut their own blanks.

Tristan