If you’re shopping knife skins and want something that feels like metal that’s actually lived a life—not a glossy paint job—the Stained family (finish aq_forced, catalog 43) is one of the oldest answers in the game. Valve leaned into a patina look: uneven green-brown oxidation sitting on bare steel, with blocks of color that read messy up close and “heirloom” from a few steps back. The flavor text jokes about lemon juice and mustard on the blade; treat that as mood, not lore you need to memorize.

The fun hook for collectors: under normal lighting it can look like grime and scuffs, but some areas behave differently under black light—worth spinning in a real server inspect if you care about that easter egg.

Quick facts (for listing filters)

• Category: knife
• Finish: Stained / 人工染色 (aq_forced)
• Rarity: Uncommon
• Style: Patina (copper-green oxidation)
• Float range: 0.00–1.00
• Origin: 14 Aug 2013, shipped with The Arms Deal on vanilla knife models (e.g. Bayonet Stained)—Valve-authored, not a Workshop submission

What wear actually changes

Stained is float-sensitive in a subtle way, not in the “FN vs BS is a different skin” sense.

• Lower wear: cleaner base metal, oxidation patches with sharper edges and stronger contrast against the steel.
• Higher wear: the face goes grey and rough; patina layers look washed out and the whole blade feels flattened.

Because each knife silhouette curves differently, the same finish lands differently on a Bayonet vs a Flip vs a Karambit. Never buy from a thumbnail alone—match the exact knife model you want, then compare floats.

How to inspect before you pay

1. On C5GAME or the Steam Community Market, pull up several listings of the same knife model side by side (same wear band if you can).
2. In-game 3D inspect: slow rotation on the spine, tip, and fuller (blood groove)—that’s where Stained either keeps layered oxidation or turns into muddy grey.
3. If the black-light gag matters to you, check under a suitable light in inspect; don’t assume every scuff is “hidden art.”

Shop verdict

Worth it if you want a 2013-era classic that doesn’t fight the knife’s shape, you like patina storytelling over loud gradients, or you’re training your eye on wear without paying premium-finish prices.

Skip or downgrade wear if you need a blade that stays high-contrast at high float, or you’re chasing flex skins—Stained is deliberately understated.

Budget tip: prioritize model + float band + spine/tip patina over chasing a “name” wear label; listings vary a lot for the same FN tag.

Editor’s aside

Stained is Valve showing off process (patina paint) before the market went crazy for dopplers and fades. It’s uncommon, not rare, which keeps it in “first serious knife skin” territory for a lot of players. I still tell people: screenshot the back of the blade—that’s where sellers hide the boring wear. And yes, peek under black light once; half the joke is that the skin rewards patience more than flex.