What's so special about Lopi yarn? Could be the long history of the breed whose wool makes up the yarn, or it could be the circumstances under which the sheep produce their wool, or it could be the way it knits up. According to the Lopi History on kertzer.com, the vikings brought sheep with them when they arrived in Iceland about eleven hundred years ago, and used them as both food and fiber sources, the latter of which was even more advantageous because the woven fiber is warm and fairly waterproof--a necessity in such a chilly environment--while still being soft enough to be comfortable. The coats of these sheep, according to Wikipedia, is made up of two separate layers: an inner layer of light, fine fibers called "pel", which is short, soft, and crinkly, and provides good insulation against the cold, and the stronger, coarser outer layer called "tog", which are more water repellent. The irregularities in staple length, when spun, lend these qualities to the resulting yarn, which is sold in three weights, and a wide range of colors:
Lopi - 100 gram balls/100 metres, 6 mm needle
Gauge: St st: 13 = 10 cm (4 inches)
Lopi Light - 50 gram balls/100 metres, 5 mm needle
Gauge: St st: 18 = 10 cm (4 inches)
Bulky Lopi – 100 gram hank/60 metres, 8 mm needle
Gauge: St st: 10sts = 10cm (4 inches)
About two weeks ago, I found some of this stuff on eBay. True, it's about twenty years old, but it's still perfectly good. Yarn, as far as I'm aware, doesn't have an expiration date. Before I started bidding on the yarn, I asked questions on the two Yahoo fiber forums to which I belong; the questions resulted in mixed responses from some of the other members: it's fuzzy and soft, it felts too easily, it's itchy, it's not itchy, things knitted from it are sturdy and likely to last a long time, it's not suited to certain projects, and so on. Ahh, a puzzle!
Since this didn't really answer the question, I decided to go ahead and start knitting something with the yarn in question. Right away I noticed that yes, it is very fuzzy, and because it's made up of loosely spun singles, it tends to pull apart if you tug the stitches too tight; this seems to be the case with any yarn that's not plied or spun fairly tight. It's so fuzzy, in fact, that someone suggested using a razor to shave any articles you knit with it... unless you favor the fuzzy look. This is not to say that it's as shaggy as the sheep the yarn comes from, I assure you!
While I didn't find it very itchy at the outset, I did find that it's a good idea to wear jeans while I'm knitting with it, because it does start to prickle after a little while, especially since the weather is hot and EVERYTHING is inclined to feel prickly. As far as softness goes, I do find it nice and fluffy, due in part to the fact that it's a loosely spun single. The only problem, though, is that those nice, soft, fluffy singles pull apart so easily that it can be frustrating. Imagine happily knitting away, and then you pull the stitch too tight, and the yarn comes apart. Far as I can tell, the only remedy for this is to just not pull the stitches as tightly as you would under other circumstances with plied yarn, which can occasionally cause some gauge problems if you're not careful.
A common complaint among knitters on the fiber forums I frequent is something called splitting, which is what happens when the tips of your knitting needles slip between the layers of plied wool while you're working; it happens to all knitters at once in awhile, but it's not fatal. Since Lopi isn't plied, however, it doesn't split the same way: the needle tip pokes through the single at points where it's getting ready to pull apart instead of between plies. Some experienced knitters suggest that splitting can be less of a problem depending on the material your knitting needles are made of; some say it happens less frequently using metal needles, while others swear it happens less often with bamboo or wood. At any rate, Lopi does just fine on my KnitPicks needles--no, that's not a shameless plug for KnitPicks--which are nickle plated.
At the moment I'm knitting a pullover with the maroon and light gray yarn, and I'm finding the experience mostly pleasant. Except when I have to keep tying the ends of the yarn together after it pulls apart. It's soft, it's lofty, it's warm even in its unknitted form, and it's certainly suited to a variety of projects, with the possible exception of socks because of felting concerns--unless you intended to make felted bedsocks or slippers in the first place.
So what is so special about Lopi yarn? It's durable and wears well. It's soft and warm, and has a wide variety of applications. And it makes a damned nice addition to the Stash.