Where to buy CURTAIN in Beijing?

Hi,
like to know where you can buy the "FLAX" to the curtain, in considerable quantities, and even sewing them.
I will arrive in Beijing on 28/06 and I will stop until 11/07/2011, so I try a dealer that sells, and manufactures, wholesale, possibly near the hotel where he lived, which is the Capital Hotel" in Qian Men East Street.

Thanks Aldo