I'm just on the front edge of looking into this. It appears that excavations have been taking place in Naqlan, Egypt on Coptic graves from the Fatimid period.
"Most of the Naqlun textiles come from the Fatimid period (AD 969-1171), although a few could be of Mamluk date (AD 1250-1517). " Quoted from:
I'm very excited. Here's another one:
"The dating of the Naqlun tunic is based on the archaeological context, which points to the Fatimid period."
Please let me know if you have further resources.