Acrylic Pouring and Paint Density

Someone in one of the acrylic pouring groups I'm in asked "So how do you determine which paint is heaviest?" I started answering in a comment, but it got longer and longer, and I figured it would be helpful to other people as well, so I'm doing this as a separate post.

First, some context, for those of you who don't know what the heck I'm talking about.

( what is acrylic pouring? )

So, how do you determine which paint is the heaviest (densest)?

( down to the nitty-gritty )

ETA: follow-up article with tables of figures