According to the press release from Milani, these pens can be used on the eyes, face, or body. Milani also advertises that these are "fine felt-tip point for easy application. They are water-resistant & long lasting." The Color Play pen comes in 6 colors: black, blue, green, grey, white, and pink. I chose to stick with the tradition shade of black.
Milani Color Play Felt-Tip Liquid Pen in Black line, .59ml/0.02 fl oz, $6.99
Comparisons with other felt liners:
Black liquid liners, left to right: ELF waterproof eyeliner pen, Milani Color Play, Lancome Artliner
Top row is thin lined, bottom is thick lined.
Left to right: ELF waterproof eyeliner pen, Milani Color Play, Lancome Artliner