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Basics about alpaca fleece
- Brief history
- Evaluation on the alpaca
- Care and preparation
South American camelids consist of two wild varieties, the guanaco and the vicuna, and two
domestic types, the llama and the alpaca. Vicuna fleece with a fiber diameter of 13-14
microns (one micron is 1/25,000 inch; human hair is about 60-90 microns) is one of the
finest and most costly fibers in the world.
Alpacas were domesticated from vicunas about 6000 years ago. An impressive feat: the
vicuna comes in one color and produces about a pound of fleece every other year; alpacas
deliver annual weights of 2-5 pounds of prime blanket fleece in shades of white, tan,
brown, black, and gray, plus pinto and other patterns.
Spaniards in the sixteenth century killed many of the llamas and alpacas, displaced them
from all but the high mountain country, and disrupted the criadores' breeding systems.
Subsequent attempts to maximize fleece weights and inter-breeding between llamas and
alpacas coarsened the alpacas' fleece. Judging from mummified alpacas, the pre-conquest
animals produced fiber of under 22 microns; most of Peru's present day fiber is over 25
microns. However, the genetics to produce that fine fleece is still within the animals; with
careful breeding, we can produce it again.
When we talk about alpaca fiber, we mean the fiber grown from secondary hair follicles
which surround a primary follicle
(the uncrimped and coarser or larger diameter fibers,
which we often refer to as "guard hair").
The more secondary follicles there are,
the denser the fleece - that is, the more fiber the alpaca is producing.
As density increases, presumably the fleece will be finer since more fibers are crowded into
the same area. The "guard hair" seems to disappear; in fact, the primary fibers are getting
finer and behaving more like secondary fibers.
Each fiber is encircled by a layer of tiny cuticle cells, or scales, which overlap each other in
an irregular pattern. (This is the reason fleece can be spun into yarn; scales from individual
fibers cling together.) The scale edges stick up and out from the fiber - .04 microns high for
huacaya alpaca, compared to .08 for wool. This means that, given a wool fleece and an
alpaca fleece of the same average diameter, the alpaca will feel finer and less scratchy
because the fibers are smoother.
Interior cells, the cortex, give the fiber strength and elasticity. Fine fibers are composed of
a high proportion of cortex. The huacaya cortex is made up of orthocortex and paracortex
growing next to each other along the length of the fiber, with the paracortex on the inside
of any wave or crimp. The crimp is what makes the fiber elastic and gives it "memory" - that
is, when stretched, then released, it returns to its original length.
Suri fibers have a unilateral cortex, fewer and much flatter scales, and less medullation,
making them smoother to the touch and more lustrous, but a little more slippery to spin.
Running up the interior of the cortex are hollow areas - medulla - more in coarser fiber, less
in finer. Alpaca (and cashmere) have smaller amounts of medullation than do other fibers.
Medullated fibers are stiff, with pointed tips that migrate toward the outside of yarn
(desirable in Harris Tweed, but increasing the itchy feel of a fabric); they reflect light and
take dye differently from more solid fibers.
When we were first learning about alpacas, we were often told that the hollow fibers
provided the warmth of an alpaca garment. But what actually makes you feel warm is the
air trapped between fibers, and finer fibers provide more spaces to hold more air.
Evaluation of fleece on the alpaca - uniformity, crimp, density, fineness, handle
This is the fun part - putting your hands into that lovely fleece.
But first, stand back and take a look at the alpaca. You want to see fleece that looks
uniform; no area should stand out.
With the sun behind the alpaca, look for a "halo" of straight fibers protruding from the
fleece; these are undesirable coarser uncrimped hairs.
Up close, you can see them as a straight tip at the end of the lock. All alpacas have them,
especially in the apron (the lower chest area) and belly, but a better quality animal will
have fewer in the blanket and neck, and its apron will start lower on its chest. However,
crias' secondary fibers are still developing; they often have a prominent "halo" that
disappears after their first shearing.
Use your hands to open and spread the fleece. Looking at a huacaya, check the lock
structure. It may be tight with many short waves per inch (high frequency, low amplitude)
or bold with tall but fewer waves. The fibers may be bundled into thick or thinner locks.
Some alpacas, like vicunas, have no apparent crimp, but each fiber shaft has a wave or
"crinkle." These fleeces can be very fine, but are probably not dense.
The frequency and amplitude of the crimp is designated as curvature, measured as degrees
per millimeter of the fiber length. Suri has low curvature of 10-35; huacaya measures 25-60.
There are some studies showing that high curvature fleeces are finer and some that show
only limited correlation.
In my opinion (you'll find others who disagree), the type of crimp (the wave along a lock of
fiber) is a matter of personal preference.
Only a skin biopsy is accurate to measure density, but you can get a rough idea. If you put
the flat of your hand against the alpaca's side, does the fleece resist your pressure? When
the fleece is opened, how much skin do you see? More skin visible means less density -
that is, there are fewer fibers per area of skin. Density, along with length, is important
because we sell our fleeces based on weight (although the price may be based on
fineness). But many breeders feel that fineness and density are opposing traits, and a
finer fleece will weigh less.
"Handle" refers to how the fleece feels when you take it in your hand or gently rub it
between your fingers. You would like to describe it as soft and smooth rather than stiff or
rough. Remember that alpacas like to roll, and a coating of dust can make a fleece feel
Suri fibers are straight so they have no crimp. There are different styles of suri locks - flat,
wavy, twisted, and so on - but if suris are sheared every year, as they should be, the lock
structure can be hard to evaluate.
I prefer to concentrate on luster; that shine is what draws me to suris, along with the silky
smooth handle. Beware, the right lighting can enhance a mediocre luster, and a cloudy day
makes it hard to evaluate.
We always want to know the "micron count." This is an actual measure of fineness - of the
average diameter of each fiber (AFD).
The standard deviation (SD) is another average: it tells us the average that individual fibers
differ from the AFD of the sample. A SD of 5 would mean that the greatest percentage of
fibers range from 5 microns below to 5 microns above the average. A low SD tells you that
the fleece is very uniform and will therefore have a soft handle.
The coefficient of variation (CV) is used as a measure of consistency; it is the SD divided by
It's reassuring to have what seems like a nice solid number to look at and use for
comparisons. We say, "His CV is 22%; he's very consistent. His micron is 22; he's very
fine." But there are a few pitfalls here. The first is that usually we're talking about a single
sample of fleece, 2 inches by 2 inches. It's a pretty good stand-in, but it's a pretty small
proportion by which to judge the entire fleece, especially regarding consistency.
Pitfall #2 is that alpacas' fleeces usually coarsen as they get older. If one breeder is
sending in fiber samples at 4 months and another at 14 months, they can't be compared. In
fact, it's tricky to compare animals from different farms, since their environment has been
Pitfall #3 is the CV, which is merely a ratio, SD divided by AFD. Two alpacas, one with a SD
of 3 and another with a SD of 6, can have the same CV, yet no one examining the actual
animals would ever judge those two fleeces as equally uniform.
I confess, I do use the CV in marketing. Our stud, Ceazar, has a CV of 15%, a very
impressive number. I expect that people who know something about micron counts will like
that number; people who know a little more will see that his AFD is also low and will deduce
that his SD is therefore also low.
Care and preparation of the fleece
Clean fleeces, desired by handspinners and mills alike, begin with clean pastures. Easier
said than done for some of us. Our farm is a filbert (hazelnut) orchard, planted in the
1930s, and we value it for its history as well as its shade. But that means our alpacas'
fleeces pick up bits of bark, nut shells, even twigs.
So the day of shearing, we clean our alpacas. The huacayas are blown out with a "reverse
vacuum." Some people actually vacuum their animals, but that hasn't worked as well for us.
The blower seems to matt the suris' fleece very easily, so they are brushed with a rubber
curry mitt, designed for horses.
If the fleece is to be entered in a show, we leave it alone; we don't want to destroy its
architecture - the lock structure, crimp, etc. We gently hand pick as much as possible before
shearing, then finish the job with the fleece laid out on a skirting table.
The shearer has removed the blanket first, then the neck, and finally the legs; these went
into three different bags. The shearer is experienced at clipping these areas separately, but
occasionally some leg wool has made its way into the first bag, or possibly part of the
blanket is shorter or coarser in one area. The next step is to skirt it - to remove vegetative
matter and non-uniform areas.
We* skirt the fleece similarly, whether it is going to a mill, a handspinner, or a show. We
pull out as much debris as possible, plus any inconsistent patches of fleece. If the alpaca
was sick during the year or suffered any other stress, we test several locks of fleece for
tenderness or breakage.
Although alpaca can be spun straight from the bag, it's usually dusty enough that most
spinners prefer to wash and card or comb it.
We put batches of fleece into a mesh lingerie bag and fill our top-loading washer with warm
water and a gentle fiber wash like Unicorn (we no longer recommend Dawn) - since there's
no lanolin, we don't need to use hot water. We gently push the bag of fleece into the
water, let it soak for 20 or so minutes, then let the washer spin it. We refill the washer with
water of the same temperature and again lower the bag to rinse the fleece, then spin it
again. We may need to repeat the washing and rinsing until the water runs clear.
To avoid making felt, we keep the water temperature constant and are careful not to run
water over the fleece or to agitate it.
After it's dried, we run it through the carder. English combs also work well, especially if the
fleece has matted.
Two breeds of alpaca with distinctly
True guard hair is stiff, straight,
and highly medullated (hollow)
fiber that is much longer than the
fleece it protects.
Guard hair keeps the softer
underlying fiber from being
damaged by grass, twigs, leaves,
shrubs, etc when the animals are
You'll find guard hair on the lower
chest (because the animal pushes
forward with the chest when it
moves) and in the armpits and
belly (where it next encounters
brush, grass, etc or accumulates it
when lying down).
*When I say "we," I mean Barry.
Some technical information from the Alpaca Fiber Symposium:
Moisture regain percentage: The amount of water a completely dry fiber will absorb from the air,
expressed as a percentage of the dry fiber weight.
*Alpaca - 8%
*Wool - 16%
*Cotton - 8%
*Silk - 9%
Alpaca has half the moisture regain of wool which could account for why it seems more comfortable and
breathable than wool.
Class I Fiber category: this means that alpaca is flame resistant. It is also marginally flame retardant,
which means it will self-extinguish.
Wicking test: In knitted or woven fabric, it does wick; in felted fabric, it does not. It is similar to wool in
absorbency and wicking.
Abrasion and Pilling: An alpaca blanket scored 3 (on a scale of 1 to 5), which is good pill resistence,
especially in woven material. It also had a score of 15,000 cycles of abrasion, which means that it met
From the AOBA Alpaca Fiber Study:
Alpaca is flame resistant;
Alpaca is water resistant, but wicks away perspiration;
Alpaca feels lighter than wool and warmer than cotton;
Alpaca is a natural renewable fiber.
Wool blindness: something
to think about when looking
at those cute fuzzy faces.