The Fixxy liner by Peach C is a slim, waterproof eyeliner available in black. According to Dibella's video review, this liner glides on smoothly and is both waterproof and smear-proof. The slim design allows for precise application, making it easy to achieve a desired look. The liner's waterproof formula ensures long-lasting wear, even in humid conditions. However, the review does not mention any potential drawbacks or specific details about the liner's performance. Overall, based on Dibella's positive comments, the Slim Waterproof Fixxy Liner seems to be a reliable and effective choice for those seeking a black eyeliner with long-lasting, smudge-proof results.