1. Look for the Silk Mark
The Silk Mark label, issued by the Silk Mark Organisation of India under the Central Silk Board, certifies 100% natural silk. It's the single most reliable check when buying online.
2. The burn test
Burn a loose thread from the fringe. Pure silk burns slowly, smells like burnt hair and leaves crushable ash. Synthetic silk melts into a hard bead and smells like plastic.
3. Feel and warmth
Pure silk warms up quickly when rubbed between your fingers; polyester stays cool and slippery.
4. Real zari vs tested zari
Real zari is silver thread coated with gold; scratch the reverse gently and you'll see silver or red silk core. Tested zari is copper-based and more affordable, and both are legitimate as long as the listing is honest.