Information on Fleece
Alpacas were domesticated over 5000 years ago by the ancient Incan culture of South America. Alpaca fibre is known for being luxuriously fine, lightweight yet very warm as well as coming in the widest range of natural colors.
When determining the quality of alpaca fleece, there are many factors to consider. these factors can be overwhelming to newcomers as some are objective (can be quantified or measured) while others are subjective (depend on personal interpretation).
We will try to explain these factors below.
FACTORS THAT DETERMINE FLEECE QUALITY
Fineness - the thickness of the fibre which is measured in microns. This measurement is represented as the Average Fibre Diameter on a test called a histogram. Histograms will be described in further detail below.
Staple Length - This is the length of the fibre from the skin to the tip. This represents the amount of fibre growth between shearings. A longer staple length also adds to a heavier shear weight.
Density - the number of fibres in a given area of the skin with more fibres per unit area representing a denser fleece. The denser a fleece is, the more it will weigh. This is desirable for heavier shear weights and the ability to process more finished products per animal.
Shear Weight - This is the weight of the fleece at shearing. Weight can be affected by genetics, diet, animal health and the time between shearings. A high yearly fleece weight is desired for processing more finished products. It is important to note when discussing shear weight whether the individual is referring to a "skirted fleece" or an "unskirted fleece". Products are made out of the "skirted" or cleaned fleece so this is the weight that you should look closely at. An alpaca could be advertised as having a 8 pound shear weight but if this refers to the unskirted fleece, the usable (skirted) portion of this fleece could be considerably less.
Color - Though this might seem like a subjective factor, color sorting is based on sight using color charts or keys that have been developed by processors. Fibre is classed into several basic categories which include white, fawn, brown, black, silver grey and rose grey. These classes are usually then broken down further as there are many variations of color within the basic categories. The result is approximately 22 or more natural shades.
Crimp vs. Crinkle - Crimp is the uniform wavy like pattern seen in fibre locks versus crinkle that does not follow a uniform pattern and occurs in individual hairs. Crimp is easy to see whereas crinkle is not as easily visible. Crimp can be measured by taking the distance between two consecutive wave peaks on a lock of fibre.
Handle - This represents the tactile qualities of the fleece, literally the way it feels. Handle is related to the Standard Deviation and Coefficient of Variation that can be found on a histogram test. It is also affected by medulation (the presence of coarse guard hairs) which is undesirable as it causes itchiness.
* Please note that all guard hairs are medulated, but not all medulated hairs are guard hairs!
Lustre - This is the visual quality of light being reflected from the fleece when viewed by the naked eye.
The ideal huacaya alpaca fleece would be fine (low micron or AFD), dense (many hair follicles situated close together in the skin), have a soft handle (feel very comfortable against the skin and lack guard hairs), bright, have a high shear weight and a long staple length.
UNDERSTANDING THE HISTOGRAM
A histogram is a test that measures several component of a fibre sample. fibre samples should be taken from the middle of the side in the blanket area of the alpaca. The samples need to be cut as close to the skin as possible and should be 2 x 2 inches thick ( approx. 25 grams). Samples also need to be labeled properly with the date taken, animal identification, sec and birthdate as these can influence the results of a fibre sample.
when you receive your results, the following information will be included:
MEAN - This is the Average Fibre Diameter (AFD) or micron measurement of the fleece sample.
STANDARD DEVIATION (SD) - The variation of fibre diameter within a sample.
CO-EFFICIENT OF VARIAITON (CV) - The spread of fibre diameter variation (SD) throughout the fleece. The lower the CV, the more uniform the fleece.
SAMPLE SIZE - The number of fibres that were in the sample that were tested.
SPIN FINENESS (SF) -This is an estimate of the sample performance if it was spun into yarn.
COMFORT FACTOR - The percentage of fibres that are under 30 microns and therefore the "prickle factor" or scratchy quality associated with the coarser fibres (fibres over 30 microns).
CURVE - The degree of curve in a fibre which is a direct correlation to crimp.
CURVE NUMBER - The number of fibres in the sample that were measured to determine the curve .