where to find Butyl?

[LennyBrooks]

ever since i saw the the repair at frets.com i have been eager to try this. I have the opportunity but can't find the Butyl is there another name or brand name for this? where can i find it?

[LennyBrooks]

Thanks everyone who replied. I ended up finding it locally under one of it's many synoms.
regards
Lenny