I wanted a brown liquid eyeliner, and after trying the brush pen liner I was going to get the Kill Brown variation, but found out that it's a really light brown. I ordered this one in Kill Brown, and it's a lovely dark brown colour. It's just as flexible as the brush pen liner, just less 'bendy'. It's just as pigmented, and just as smooth - if not smoother over eye primers - and can have varying line thickness. It is the middle swatch on the second image, and the line thickness variation as well as really good pigmentation is displayed. It doesn't smudge on me when I set my undereyes really well, and it's definitely a staple now! Going to buy more as gifts now!