Originally Posted by
tiger1964
I just looked for Kapton, and I presume it's not a bike-specific product? Unsure on sourcing...
Yeah, it's not a bike-specific product. Most "tubeless tapes" are actually rebranded strapping tapes. After my other post, 1/2" might be on the narrow side; 5/8" might be a better fit for vintage 700C rims:
https://www.kaptontape.com/1_Mil_Kapton_Tapes.php
Well, that's an option. Wow, almost ten bucks and I presume that's per wheel? Not per pair?
"
Sold per pair (enough to complete one wheelset)." And it's reusable. 
Disclaimer: I haven't used the above products specifically. But Pacenti blue tape and Stan's tape work on the same principle.