The only chance you'll ever get to see all of India in a day, every November the Pragati Maidan exhibition centre hosts this enormous trade fair. Sounds dull, but there's stands representing every state of India and it's a great chance to see a little slice of each. The 'SARAS' hall of rural handicrafts is a particular must, with wares from Kashmir to Orissa all in one place at very decent prices.
Check to see when it opens its doors to the public, and try to get a ticket from outside retailers rather than queuing. It gets busy and traffic is awful, but drivers should know the location Pragati Maidan.
I recommend it because Karachi has lots of places from where you can get the local handicrafts. Unfortunately, most of them just fleece people. Saddar is one place where you can get a good thing at a reasonable price. Please note that Saddar bazar is a collective term that I have used to indicate an entire place in Karachi. There you will find lots of leather bags, bangles and other things. Look for marble items there as well.
Corporate market and Zainab market.
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