I made this table up for myself when I became a wool-freak
, it may help to give an idea of wools and their qualities. I think Merino is often used because it is very fine and so good for underwear; it's probably cheap as I think (could be wrong) they have enormous flocks in South Africa where much of the Merino used grown; and good for machine knitting which is how commercial garments are made. Machine knitting is tighter than hand knitting and will have less "loft"; it's also much faster and more profitable than hand knitting - which is a money loss to us all who do it! There is (at present) far less of the other wools in the table than there is Merino which will be another reason for its use.
Manufacturers will hype the good qualities of Merino (which are good) in a manner that suggests it is the king of wools, this isn't necessarily so, it depends what you want to use it for.
Wool types
Merino 18.5-25.5 microns so it is the finest wool in terms of strand thickness, 75-80mm length of staple (i.e. each strand length). Good for thin garments like underwear, delicate jumpers and machine knitting. Often from South Africa
Blue Faced Leicester 26 Micron so very fine, 85-90mm and medium long. Good lustre with good resilience and highly prized for its likeness to mohair.
Shetland 29-31mic thickness so thicker than Merino, 90mm staple so longer than merino: fine, soft and silky to the touch with a good, bulky down characteristic, has good lustre. Good for anything, jumpers, vests, socks, gloves, can be knitted very fine or thicker for gloves and socks, outer garments.
Welsh 31-35 microns so thicker than both Merino & Shetland, 80-100mm so longer than both Shetland and Merino. The only pure black sheep in the UK. I find it works best for socks and jumpers.
Jacob 33-35 Micron so fairly thick, 85-95mm so short. Rough, tough stuff, maybe welly-socks. It’s not as “carpet” as Herdwick!
Icelandic 34-36 Micron so thicker than all the above, 90-100mm so similar to welsh in length. Good lustre, one of the best felting wools in the world; lightweight, water repellent and breathable. Good for outer garments.
Herdwick 40 microns so thick, 85-90mm so short. A coarse quality hard wearing wool commonly known as “carpet sheep”.
Teeswater 40-60microns so very thick, 150-300mm staple so very long, it’s also curly and lustrous. It’s long length makes it much nicer to the touch than Herdwick although it’s thicker. Makes good thick wool for tough outer garments.
Cheviot 30-35microns so about as thick as Welsh and similar in length, 80-100mm. The fleece varies in quality from fine to coarse, not too crimpy and quite resilient, so good for filling purposes, like cushions.
Devon 40-60microns so quite thick but very long at 200-250mm. It’s very heavy wool, good for felting and excellent for woven fabrics.
Swaledale 35-45microns and length, 100-200mm. Predominantly used in carpet yarns and rug yarns due to its excellent resilience and hardwearing properties.
Wensleydale 40-50microns and 200-300mm long. It’s a lustrous long-wool, often blended with finer but shorter stapled wools, where a strong yarn is required.
I also use Ryland (native to Hereford, where I live) and North Ronaldsay, the Orkney sheep that feeds on seaweed. Ryland is supposed to make wool good for fine stockings, the first Queen Elizabeth refused to have her stockings made from anything else. I find North Ronaldsay wool superb for boot socks.
