So I’ve read a pretty promising forum post about this, and a few ladies on it tested it out too. What you do is if you are not sure if it’s a vvvvfl or evap, you put a drop or two of water on the part that you pee on or add your pee drops too. If it’s an evap line, it’ll disappear. They say it’s because evaps are just ‘dry’ and that’s why you see them but if it’s wet they’ll disappear. So if it really is a positive it’ll stay. What do you think?

Obviously this isn’t something that I take 10000% seriously. Mostly for fun, but still curious!