I may have found a source where I can buy prepared nettle fibre for spinning. This is Julie Northcott-Wilson of Northcott Wilson Artisans, who is going to talk to her suppliers in Asia about the possibility.
Northcott-Wilson sells skeins of handspun nettles as well as other interesting fibres.
In the baskets of skeins you can see from left dyed banana fibre—which is harvested from spent branches—sari warp thread, unspun sari cloth remnants, and spun sari cloth remnants just peeking out of the back far basket.
You can see in the middle the spun sari cloth skein's firm texture compared to the unspun sari cloth skein on the left. (Click to enlarge.) Northcott-Wilson says either skein lends itself well to weaving but each gives a different effect.
The spun warp thread skein on the right is suitable for crochet and knitting.
At her booth last weekend in Williamsburg's Merchant Square I got to see these skeins along with her line of bags, some of which were made of nettle fibre.
Reclaimed silk fibre for spinning is available at her online shop.
I found a reference on Etsy from another vendor that nettle fibre is considered a moth repellent and is traditionally used in Asia to back wool rugs.
Aha! I could use nettle fibre as tapestry warp thread to make a wool weft-faced wall hanging that would last and not get moth-eaten. Assuming I can spin strong warp thread. Assuming I learn tapestry weaving. Assuming I get a tapestry loom. Assuming nettles do repel moths. Northcott-Wilson says the smell does repel people.
She adds that the smell of nettles can be removed through prewashing if desired or left to dissipate, which it will do after a few weeks.
Do not store up for yourselves treasures on earth, where moth and rust destroy, and where thieves break in and steal.
Matthew 6:19 NIV