To tell if a Louis Vuitton Supreme belt is real, examine the engraving on the leather part of the interior side of your belt. Fake belts often have text that appears either too thick or thin. 1. Engraving. Authentic: Appropriate thickness and engraving depth. Fake: Text appears too thick due to it being engraved too deeply into the leather.You can tell if a Louis Vuitton belt is real or fake by checking the text inside the belt. Fake belts have noticeably thicker inscriptions. 1. LV buckle. 1.1. Monogram belt. Authentic Louis Vuitton Belt: Sharp corners are characteristic of authentic Louis Vuitton belts. The bottom of the “V” maintains sharp corners on authentic belts.