Assessing alpaca fleece

By Nic Cooper from Southern Alpacas Stud

Alpaca has a fantastic name as a soft high quality, high value fibre. Let's look at what makes an excellent fleece.

Fineness

Diagram - the position to
take a mid-side sample

In all commercial fibre processes it is largely the fineness (micron) of the fibre that dictates the price - the lower the micron, the finer the fibre, the higher the price.

"Micron" is the diameter of a single strand of fibre. A single silkworm thread is 1 micron and the finest of human hair starts at around 60 micron. The finest animal fibre is the vicuna - the camelid from which the alpaca was domesticated - at about 12 micron. Alpaca range from 12 micron through to 40 micron.

Price-wise 16 micron alpaca sells for over $60 per kg, whereas 40 micron alpaca sells for under $1 per kg in bulk to processors.

Dealing with micron that fine, it really has to be measured to get it right and measurement is done by various wool testing houses using a range of machines to produce a "histogram".

Graph - a histogram of an alpaca fleece sample

Histograms do provide scientific independent measured data about an alpaca fleece. A histogram is supposed to represent the fineness of the fleece, and the evenness of distribution of that fineness throughout the fleece. It is a snapshot in time, and can change considerably as the animal changes location and hence environment, grows older or eats different foods.

The histogram is produced by taking a sample of fibre from the mid-side of the alpaca. This location best represents the average micron of the fleece.

Each fibre diameter is measured and plotted on a graph showing the fibre micron on the x (vertical) axis, and the number of fibres at that particular micron on the y (horizontal) axis.

The machine will calculate the average of all the fibres measured (the "mean micron"). When alpaca owners quote a micron figure for an alpaca they usually quote this average.

A histogram will also tell you more about the fibre being measured - such as the uniformity of the fibre (SD standard deviation and CVD coefficient of variation - both the lower the better) and some specific calculated measurements such as CF (comfort factor - how much it does not prickle - 100% is best) and how the fibre reacts in a spinning situation (SF spin fineness).

Shear weight

Photo: Alpacas shear fine fibre in a
range of natural colours

This is the amount of fleece you get off an alpaca, and it is usually expressed as an annual adjusted weight, so you know how much fleece an alpaca grows a year. Annualised shear weight depends on a number of things - the speed of growth of fibre, the body area shorn, the concentration of fibres in a particular area and the micron of those fibres.

Shear weight is important, as the more you shear, the more you can sell. All alpacas are shorn so the shear weight statistic should be readily available.

Colour

This is a matter of personal preference, however, with the odd exception, the lighter colour alpacas have better developed fleece characteristics.

Whatever colour is chosen, the colour should be uniform with no contamination of fibre with other colours (e.g. white fibres in a black fleece or dark fibres in a white one). The exceptionis grey fibre which is by definition a mixed colour, with white, black, brown and various shades of grey often being present.

Crimp

Photo: A lustrous fleece
with a "wow" crimp

Crimp is the corrugated effect of the fibre, seen when the fleece is opened. It is the most obvious aspect of the fleece and has a "wow" factor, so is emphasised by many breeders. In viewing a fleece, a crimp style can be indicative of other valuable characteristics such as fineness and density.

In reality crimp is viewed differently by processors - for some it adds value (loft for woollen garments for example), for others it is irrelevant, and if needed can be added in the processing.

The author

Nic Cooper has been breeding alpacas for 20 years concentrating on achieving a uniform commercial fleece herd. In the past few years the fleece from the Southern Alpacas Stud herd has been processed into some of the finest and sought after alpaca yarns available. An alpaca judge, Nic has been instrumental in changes made to bring fleece judging closer to commercial reality.