It seems like pen style liquid liners are the trend lately and Chantecaille jumped right on the bandwagon. Le Stylo comes in 3 shades: black, indigo and brown. The pen is thick but not too thick. It is thicker than the Le Metier pen style liner. The ink is very pigmented and goes on smoothly and I find I do not need to do many coats to get a nice black line. For reference, I use the tap method where you lay the pen on its side and tap it along your lash line.
This swatch is just a drawn on line. I find the tap method gives better pigmentation. As far as lasting power goes, I am a bit disappointed. It doesn't flake but I do find black under my eyes pretty quickly. For reference, I live in a slightly humid area and am prone to get oily eyelids.
Overall, I would recommend this liner to people who have dry lids and are not looking for something waterproof. It is $26 and can be found at all Chantecaille retails.