After reviewing some liquid liner tutorials, I gave my Lineur Intense a go at a three-day summer music festival. It went on smoothly over eye shadow primer, creating pretty clean lines on the first try. (The edges got cleaner with each application, so I think technique and light pressure are key.) A stray mark was easy to remove with a cotton bud and a drop of water.
This liner shrugged off heat, humidity and sweat, looking good even at the end of 16-20 hour days. Zero transfer. Minimal flaking when rubbed. And it all came off cleanly with real soap and water at the end of the day.