What a pattern index is
Every skin has a pattern seed between 0 and 1000 that decides how the texture is positioned. On most skins you would never notice, but on some finishes it changes everything. The seed is fixed for each item and never changes.
Case Hardened
The seed decides how much blue, gold and purple is visible. Specific seeds on specific weapons are known as blue gems and can be extremely valuable. See the blue gem guide for tiers and how to verify them.
Fade and Marble Fade
On Fade the seed sets the fade percentage; on Marble Fade it decides patterns such as 'fire and ice'. Collectors pay premiums for the most sought-after looks. The fade percentage guide covers the details.
Doppler
Doppler phase is separate from the seed, but within a phase the seed still changes the look – for example how much black or how many bright spots appear. Always check the exact phase first, then the pattern.
Verify before you trade
Use inspect links and screenshots of the exact item. Do not rely on a listing title or catalogue artwork to prove a pattern. If in doubt, ask our support team before you buy or sell.
Sources and further reading
Ready to sell?
Load your inventory and see your price instantly.