Definition
Pattern index — also called paint seed — is a 32-bit integer Valve writes onto a CS2 skin at the moment it generates the item, alongside the float. It controls which slice of the source texture the in-game skin samples from. The number itself ranges from 0 to roughly 1000 on most skins.
For the vast majority of skins, the pattern is cosmetic noise — two AWP Asiimovs in the same exterior look effectively identical regardless of seed. For a small list of finishes, the seed is the dominant price driver, often eclipsing both float and exterior. The full taxonomy of which skins this hits is in our items encyclopedia pillar and the knife patterns deep-dive.
The four patterns the market actually trades
- Case Hardened "blue gem" — AK-47, Five-SeveN, Karambit, Bayonet, M9 Bayonet, MAC-10 and a few other Case Hardened skins sample a stained-blue Damascus texture. A handful of seeds (seed 661, 670, 955 on the AK) produce nearly all-blue playside finishes. Tier-1 blue-gem AKs trade in five-figure USD as of 2026; tier-3 (mostly-blue) copies still command 5-10× an off-pattern Case Hardened.
- Fade percentage — Karambit Fade, Glock-18 Fade, AWP Fade, Bayonet Fade are graded by the percentage of rainbow gradient visible on the playside. 100% / 90% / 80% are the public tiers; a 100% Fade commands 30-50% premium over a baseline 80%.
- Doppler phases — Doppler knives split into Phase 1 / Phase 2 / Phase 3 / Phase 4, plus the rare Ruby (red), Sapphire (blue), and Black Pearl finishes. Black Pearl and Ruby are the headline phases; Phase 2 is usually the cheapest. The full phase reference lives in the Doppler guide and the post-Gamma reissue is covered in the Gamma Doppler guide.
- Crimson Web "full web" — M9 Bayonet and Karambit Crimson Web sample a webbed texture. Copies showing a complete uncrossed spider web on the playside trade at 3-8× the price of a "half-web" copy in the same exterior.
Pattern vs float: which one wins
On a collectible pattern, pattern dominates. A blue-gem AK-47 in Battle-Scarred is still a blue gem, and the pattern premium absorbs the float discount — buyers care about the playside visual far more than the wear coordinate.
On a finish where the pattern controls only the color (Doppler, Gamma Doppler), float still drives a meaningful share of the price because the phase has already settled the visual identity. A Doppler Phase 4 in Field-Tested looks worse than the same phase in Factory New, even though the color is identical.
The general rule: the further the seed is from "normal", the less float matters.
How to check the pattern of your own skin
Use the inspect link (steam://run/...) Steam exposes from your inventory. Tools like CSFloat and a few community pattern checkers read the inspect token, return the seed number, and overlay the pattern on a reference grid (blue gem zones, Fade %, full-web map, Marble Fade FFI position).
The pattern number alone is not enough on Case Hardened — the same seed produces different finishes on AK vs Karambit, because the texture sampling region differs by weapon model. Always cross-reference the seed against a per-weapon tier list rather than a generic table.