These spiders are found in the highlands of Madagascar. They are captured each day to produce silk and then freed at the end of each day. They cannot be kept in captivity due to their cannabalistic nature.
24 spider threads are used to make one thread. This 24 strand thread is then carefully woven into various patterns some of which include the spider.
I was at the 'Make It!' craft show on Sunday and visited the Japenese Embroiders Guild, do checkout their website their work is amazingly intricate, and I ended up chatting to the ladies for quite a while about the spider silk and showing them the photos on my iphone.
Anyway if you are passing the V&A I recommend popping into room 17a.