Lopi comes from the distinctive Icelandic sheep. Their fleeces have two layers, each with its own kind of wool. The sheep’s outer coat is water-repellent wool made up of long, tough fibres (called tog) and the under coat is highly insulating, made up of fine, soft wool (called thel or þel). The two fibres are blended in lopi yarn, combining the different qualities of both kinds of wool.
The yarn seems light relative to its bulk, less dense than most knitting wool. It is spun without the definite twist of other woolen yarn. The name lopi originally meant wool that hasn’t been spun at all, and today’s lightly-processed yarn developed from experiments in the early 1900s by knitters using completely unspun wool.†
Despite the variety of undyed natural colours and traditional-looking Nordic sweater designs, lopi was a “modern” invention stemming from industrial wool processing. It wasn’t well-known before the 1920s, even in Iceland.
Because the fibres are not spun tightly, the yarn breaks easily, but it’s also easy to repair breaks. You can get good results when joining two pieces together by splicing.
Felting works well for the same reason that joining two ends is quite simple. The structure and texture of lopi wool means it will easily form a matted, felted surface. So take care when washing and drying knitted garments that you don’t want to felt.
Lopi yarn is used for the characteristic Icelandic sweater called a lopapeysa. These sweaters are often knitted in the natural colours supplied by different sheep – shades of creamy white, grey, brown, and black. On big needles the bulky yarn knits up quite quickly, and thick, warm garments don’t take too long for a craftsperson with a little experience.
An Icelandic sweater is knitted with a one-piece patterned yoke where the design follows the circular shape. You need enough skill to handle two colours in one row, but otherwise the technique is really quite simple. By making the yoke “in the round”, on circular needles (or with four double-pointed needles), you can use plain knitting (no purl) all the way, and many people find this helps with stranding the out-of-use colour along the inside. The yoke is knitted on stitches picked up from the top of the sleeves and body, with these also having been made as tubes without sewn seams.
If you want the satisfaction of knitting something fast with lopi wool, you may decide to start with a hat. If you choose a sweater, be sure to pick a pattern to suit one of the thicker yarns – the popular Álafoss lopi or possibly Bulky-lopi. Létt-lopi (aka Lopi Lite) is much lighter, and gives you a chance to make clothes with a different look from the lopapeysa, but it is knitted on finer needles and takes more stitches to the inch.