Normal gun skins are not eligible for level ups.
Exclusive skins can be acquired from certain paid crates by a certain chance.

New effects are added for different levels.

"Sophisticated surface treatment" and "Parts level-up" items are required to level up gun skins.

Basic appearance: Basic status of upgradable skin
Kill special effects: New effects are displayed when knocking down enemy
Upgraded: New looks to the upgradable skins
Kill alert: New kill alert effects
Results emote: When attaching this weapon, special results emotes are played on match results page
Hit special effects: When hitting opponent, effects change.
Ultimate: New looks to the upgradable skins
Looting box: New looks to looting box when enemy dies

※ Experiment lists may vary between weapons

"Sophisticated surface treatment" can be acquired from the store by spending Silver pieces.

"Parts level-up" item can be acquired by decompositioning the dedicated skin.
(It can only be decomposed when player owns multiple number of same skins)

Skin's grade may vary depending on the upgraded level.

The above effects are only available when upgradable skin is applied to the gun and used in-game.