Lightweight but relatively strong conductive ribbon

Subtle reminder that I have to return some videotapes.

Conductive

Seems like the tape would get burnt up before too much damage was done though.

Yes, but across sufficiently high voltage lines the initial arc would create a plasma channel which would act like a thick wire for the short to continue

I guess it's probably not enough to sustain a long time and there are probably protections in place to prevent that.

Here is a short video showing someone doing almost exactly this: https://m.youtube.com/watch?v=X_2lZqyCmls

Pretty confident that video is fake. The concept holds though. This video seems more realistic. https://youtu.be/2NKOlLDNknc

Point being the initial path creates a plasma channel that then bridges the gap and lets current flow.

So I would expect an outcome like 3 or 2 in this video (where something bridges the lines, established the arc, and then it goes away):

https://www.youtube.com/watch?v=gOT8jx4jEzM

Is the arc dissipating because an automatic system is killing power to the lines? Is there going to be damage elsewhere in the system from events like 3 and 2 in the video there?

No it works pretty well. You're essentially making a thyratron.

https://en.wikipedia.org/wiki/Thyratron