Skins are unlocked by gaining XP in matches and increasing your Player Level.
Guide :: How to set a custom skin - Redmatch 2 - Steam Community redmatch 2 skins
The "Custom Skin" feature is the standout element for most players. Skins are unlocked by gaining XP in matches
However, some higher-tier skins offer a subtle psychological edge. A flashy, neon Revolver skin might intimidate a less experienced player, while a sleek, minimal skin might signal a veteran who doesn’t need distractions. while a sleek