The textile market around Masjid India is the best place in KL to buy fabric for traditional Malay dress — batik (hand-drawn and printed), songket (silk brocade woven with gold and silver thread), and brocades for baju kurung and baju kebaya. Stalls and shophouses in the lanes around the mosque sell by the metre or as pre-cut pieces, and the prices are well below what you'd pay in malls. Several tailors operate nearby if you want clothing made up.
The market is concentrated in the lanes east of Jalan Masjid India and on Lorong Bunus 6 and 8. It's at its busiest before major festivals (Hari Raya Aidilfitri, Hari Raya Aidiladha) when the neighbourhood fills with shoppers buying cloth for new outfits. Prices are negotiable; knowing roughly what you want before you arrive helps.