I got some Finn fiber blended with 20% nylon (trilobal, I think, which is a bit sparkly) via a Ravelry group that is interested in trying different sock blends. I dyed it up myself using an iDye packet and spun it up and knit up some nice manly blue socks. They fit well and the initial products were pleasant and my husband wore them to work.
Then I washed them.
After a mere 3 cycles through my usual laundry routine - which is, as loyal readers know, involves a Euro front-loader, delicate cycle, cold water, and air drying - they are completely and totally felted. A ruined mass of wool.
[close-up of felted knitting]
Finn is a fairly fine wool, and in retrospect I should've known this would not be a happy choice. It is great for felting. Ergo, it is not great for socks, unless you're after slippers, I guess...
Lesson learned. No more Finn for me.