From one who worked in the wool classing business in my youth just a few cautions to observe.
Many factors determine the quality (and value) of wool.
These include fiber diameter, crimp, yield, color, purity, and staple length and strength.
Fiber diameter, also called fineness, is the actual measurement of the thickness of the wool fiber. It is measured in microns, which is one millionth of a meter.
It is the fineness of the fibre that determines its pricklyness. The finer the fibre the less the prickle.
So, clothing worn directly on the skin, the base layer, singlets undies and T-shirts, should be made of the the finest wool fibre possible. This is not so important when it comes to mid and outer layer garments used for hiking.
The 'very' fine wool used in the manufacture of 'fine' garments today appears to consist of a range of microns, with the finished garment 'averaging' around 17 microns.
If you are lucky you will find the micron measurement of the wool used on the tags attached to the garment, or on the manufacturer's website.
If not, you take your chances.
One final point. Hold the wool fabric up to a light. Stretch it a little. The less blotchy it appears the less the range of micron fibres used in the weaving.
So, as an initial guide to baselayers, look for light, thin fabric, with little blotchiness.
This is often expensive. For good reason.
Regards
Gerard
