Pattern indexes: Case Hardened, Fade, and Marble Fade — the collector's guide
Some CS2 skins ignore float almost entirely. Two AK Case Hardeneds with the same float can trade for €40 and €4000. The reason is a hidden integer called the pattern index. Here's how it works and how to spot the gems.
Float gets all the attention in CS2 trading — the 0.000-to-1.000 wear number that controls how a skin looks. But for a specific family of skins, float is barely the third-most-important attribute. The two attributes that matter more are finish style and pattern index.
This article focuses on the three classic pattern skins: Case Hardened (blue gems), Fade (full fade percentage), and Marble Fade (Fire & Ice and similar). Same mechanics apply to Crimson Web, Slaughter, Doppler, and a handful of others — the principles transfer.
What is a pattern index, technically?
Every CS2 skin is assigned, at unbox, a 32-bit integer called the pattern index in the range 0—1000. This integer seeds the procedural placement of the camo texture on the weapon model. For most skins (e.g. AK-47 | Redline), changing the pattern index produces a barely-perceptible shift. For Case Hardened, Fade, and Marble Fade, it’s the difference between a chunk of metal and a museum piece.
The reason: those three finishes use procedural textures that depend strongly on rotation/UV seed. The camo pattern is generated deterministically from the pattern index, so a Case Hardened with pattern index 555 looks identical on every copy ever unboxed with that seed.
Case Hardened: the blue gem game
Case Hardened skins (AK-47, Five-SeveN, M9 Bayonet, Karambit, and more) use a heat-treated steel texture that ranges from gold to purple to blue. The blue is the prize. The community measures “blue” in two ways:
- Tier ranking by community-curated lists (CSBlueGem, PatternFinder, etc.). Tier 1 = the best of the best (e.g. AK pattern 661 has nearly a full blue top).
- Blue percentage on a specific face of the weapon. For AK-47, the “playside” (left side from first-person view) is what most buyers care about. Blue % on the playside is the single biggest price driver.
Example: an AK-47 | Case Hardened (Field-Tested) at default pattern sells for €30—€50. The same skin at pattern 661 (the most famous blue gem) clears €25,000+. Float barely matters when the gem is in play.
Tier list for AK Case Hardened (broad strokes):
| Tier | Approximate price multiplier | Example patterns |
|---|---|---|
| Tier 1 | 200x—500x base | 661, 670, 868, 321 |
| Tier 2 | 30x—80x | 179, 387, 555, 760 |
| Tier 3 | 5x—15x | Various with significant blue on one side |
| Common | 1x | Most patterns; gold/purple dominated |
Fade: percentage to full fade
Fade skins (Glock-18 | Fade, AWP | Fade, Karambit | Fade, etc.) get a yellow-to-purple gradient. The pattern index controls where the fade starts on the model. The community measures fade percentage — how much of the visible model carries the full multicolour gradient.
100% fade = the entire weapon shows the full gradient (highest visual impact). Most patterns sit around 80—90%. Below 80% the gradient gets cut off and the weapon looks less spectacular.
Practical pricing: 100% fade trades at 1.7x—2.5x compared to a 90% fade of the same skin and wear. Below 85%, no premium. Below 80%, there is sometimes a discount versus the “clean” average.
Marble Fade: Fire & Ice and other variants
Marble Fade skins (Karambit, M9 Bayonet, AK-47 | Cartel, etc.) get a four-colour bleed of red, yellow, blue, and green-tinged shades across the model. The pattern index controls where each colour sits.
The collector’s prize is “Fire & Ice” (FFI) —a specific arrangement where the red side and the blue side are cleanly separated on the visible face. There are a small number of FFI patterns and they trade at 3x—10x the base.
Then there’s “Max Effective” tier (red bias on the playside) and various lesser tiers. Knife Marble Fades have the most active pattern markets — weapon Marble Fades have less differentiation but still meaningful premium for top patterns.
How to buy pattern skins safely
Pattern markets reward research and punish impulse. Three guardrails:
- Verify pattern in-game inspection. Don’t trust a listing screenshot — use the in-game inspect link. The seed is deterministic, so the rendering is identical across screenshots but you want to verify with the official inspector.
- Cross-reference tier lists. A seller advertising a “Tier 1 blue gem” should be verifiable on at least two community sources. If the pattern shows up nowhere, it is not Tier 1.
- Float still matters for visibility. A blue-gem AK at 0.39 (Field-Tested upper) will show pattern-on-grime, which collectors dislike. Lower float = clearer view of the pattern. For weapon Case Hardeneds, the value premium for low float can stack with the pattern premium.
When pattern matters for flipping, not collecting
Most flippers should ignore patterns entirely. The market for top patterns is illiquid — you can wait six months to sell a Tier 1 AK Case Hardened at the “correct” price. Holding carries real opportunity cost.
The exception is mid-tier patterns where the discount-to-tier market is large. A Tier 2 AK pattern listed at default pattern price is +200% in theoretical resale. If you can spot it on a venue where the seller didn’t flag the pattern (Skinport often does not surface pattern index by default), it is a real flip.
SkinScope highlights pattern-flagged listings on the Scanner when a listing’s pattern index appears on any of our pattern tier lists. The signal is rare; when it shows up, it deserves immediate attention.
Patterns are the most opaque corner of CS2 trading. Most players never touch them. For collectors and patient traders, the underpriced patterns are the only place in the market where a single click can compound 5x or more — as long as you’ve done the homework first.