Protect yourself from being suckered the next time you're looking to buy a set of real silk sheets or a real silk cheongsam by remembering this simple test
The Burn Test
Pull out a loose thread from the silk product you're interested in. Now burn it.
What Should Happen
The thread should simply ball up and turn to ash when lit.
The burning silk should smell like burning hair. (Both substances mainly consist of a fibrous protein ĘC fibroin in the case of silk and keratin in the case of hair.)
The ash should be black and crispy/brittle.
As soon as the flame is removed, the thread should do nothing more (no further burning).
What Should Not Happen: Dead Giveaways to Artificial Silk
The thread should not melt/bubble/drip when lit.
The burning silk should not smell like burning paper. (Rayon is a popular silk substitute, and like paper, mostly consists of cellulose.)
The ash should not be soft and chalky.
The thread should not continue to burn after the flame is removed.
Note: If You're Buying Silk Fabric
If you're buying silk fabric right off the spool, perhaps to have something custom made, you might be interested to know that fabric manufacturers in China are required by the government to attach fabric identification tags to their goods. Therefore, check the spool with the silk you're interested in for its tag. On it there should be a five-digit number. Reading from left to right, if the first number is a "1", then the fabric is 100% real silk.
But keep in mind fake tags are even easier to produce than artificial silk. Rely on the burn test above all else.