Verified answer

I would go to the hardware store and look/ask for metal duct tape. It is a lot like aluminum foil but on a narrow roll and sticky on one side after the paper back is removed. It is what professionals use on furnaces and venting. It is about $10 a small roll compared to $3 for a similar cloth/vinyl duct tape.

Better for what? If you want it to use on ducts, you can buy some very shiny metal tape in any place that sells heating duct stuff. It has no strength, though, and tears easily, because it has no fabric backing like the other kind of duct tape. All it does is seal air leaks in ducting, which it does very well, or look shiny on things you put it on. If you want the fabric backed stuff, buy an expensive version with a brand name on it and not a dollar store version.

Shurtape and Permacell are both very good brands. Shop around for a good price, they're not cheap, but they are worth it, when needed.