Currently a rare fiber used in outdoor apparel, alpaca is extremely soft and offers a high warmth to weight ratio. Found in a few sock lines such as Dahlgren, alpaca has now graduated into an entire collection of activewear from Washington based company Woop!Wear.
Alpaca fiber is sustainably harvested from the South American domestic animal with the same name, where the alpaca are bred specifically for their fiber and not used for labor. The naturally lustrous fiber comes in over 20 different natural colors, producing a variety of products without added dyes.
For their line of activewear, Woop!Wear uses what the industry calls baby alpaca (not age but fine fiber), which is less than 21 microns thick. This compares to the thickness of fine, Merino wool. Alpaca fiber has a flat, low-profile scale (about half that of wool), giving alpaca a nice, smooth feel.
Woop!Wear claims that alpaca offer more warmth than wool for the same weight. With a hollow core, alpaca fibers trap air, warming up quickly and staying insulated over a longer time. Alpaca is naturally durable, moisture wicking, and hypoallergenic as well.
The Woop!Wear activewear collection currently includes men's and women's base layers, along with hiking pants, shirts, and pullovers. Prices range from $73 for a base layer top to $169 for the alpaca hiking pants.
Update: I spoke with Gina from Woop!Wear. All products currently on the site are for shipping August 2012. Sizes will range from S-XL in all the styles except the field pants which will be available for women size 4-12 and men sizes 30R-38R and 30L-38L. Regular inseam is 32.5 inches and long inseam is 34 inches.