Whence afghan?

I'm not sure. That's just what I was brought up to call a knitted/crocheted blanket. It's in the Merriam-Webster:

Main Entry: Afˇghan
Pronunciation: 'af-"gan also -g&n
Function: noun
Etymology: Persian afghAn Pashtun
Date: 1767
1 a (1) : PASHTUN (2) : PASHTO b : a native or inhabitant of Afghanistan
2 not capitalized : a blanket or shawl of colored wool knitted or crocheted in strips or squares
3 not capitalized : a Turkoman carpet of large size and long pile woven in geometric designs
4 : AFGHAN HOUND
- Afghan adjective