Choosing the Best Yarn for You

Natural fibre knitting yarns can be made using different fibres constructed in a whole host of ways to give endless variety.

To help you choose the best undyed yarn for you, check out our guide to some of the more technical yarn descriptions.

A wide variety of natural fibres can be used in knitting yarns. Some of the more popular choices are alpaca, merino, silk, mohair, camel, silk, wool, bamboo, cashmere and linen. Each originates from different animals / fibres and has its own individual properties.

To make choosing easier, several types of natural fibre are divided into sub-categories based on the fineness of the fibre. The fineness (literally the thickness of each fibre) denotes the diameter of the fibre and is measured in microns (1 micron = 1/1000 of a mm). This is the main characteristic that determines the relative softness and price of fibres when compared with other fibres of the same type.

While different natural fibres have the same fineness (eg. 21 micron) this does not mean they are the same softness. So for example, though they have the same fineness, 21 micron Merino will not feel as soft as 21 micron Alpaca.

Undyed Yarn Group 4 scaled

Fibres and Fineness

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Here are common names for fibres according to their fineness:

Our merino wool is sourced from South America and comes from areas that do not practice mulesing. Available in a range of pure and blended yarns, a variety of plies, and as superwash or non-superwash, all our merino yarns are beautifully soft and can be comfortably worn next to the skin.

Merino Sheep

Yarn Count Explained


The number and thickness of each strand gives the overall thickness/weight of the yarn. The more strands or the thicker each strand is determines whether the yarn is a lace or chunky weight yarn. The number and thickness of each strand is given by a set of numbers known as the ‘count’ eg. 4/16 nm, 2/16nm, 3/11nm.

The first number indicates the number of strands that are wound together to make the yarn. If you carefully pull a length of yarn apart you can count the strands. The second number is the length of 1 kg of 1 strand in thousands of meters.

So, a standard sock yarn might be 4/16nm, meaning it’s made of 4 strands. 1 kg of each strand would be 16,000m long. There are 4 strands, so 1kg of the yarn is therefore 4,000m long and 100g is 400m long.

A standard lace weight is 2/16nm, meaning it is made of 2 strands. 1 kg of each strand is 16,000m long but there are 2 strands, so 1kg = 8000m, 100g = 800m.

Technically, each strand is called a ‘ply’ and this is why lace weight yarns are called ‘2 Ply’ and sock weight yarns are called ‘4ply’. Sometimes you hear of DK yarns being ‘8 ply’.

‘4 Ply’ has become a generic term to mean all yarns about 400m / 100g but not all yarns this length have 4 plys. Our Extra Fine Merino 4 Ply is 1/4nm. It’s a single strand (ply). 1kg of the strand is 4000m / 100g = 400m.

Superwash Yarns

All superwash yarns from Rooster Yarns are Oeko-Tex100® certified. Oeko-Tex100® is a globally recognised standard for textiles. Products certified with Oeko-Tex100® have undergone stringent tests for harmful substances and every component confirmed as harmless for human health. You can be sure, therefore, that all our yarns are produced to the highest environmental standards.

The process used to create our superwash yarns is the Hercosett method, an industry standard for making machine-washable wool. The method alters the wool fibres to ensure the yarn will not shrink or felt when machine-washed. While chemicals are used in the process, they are managed under stringent conditions to satisfy the Oeko-Tex100® standard.

The textile industry is undertaking ongoing research to identify other superwash methods, however, so far none of the other methods are as effective or widely available.

Of course, wool does not have to be superwashed and we have a wide selection of wonderful non-superwash yarns . For these, we recommend hand washing rather than machine washing.

View non-superwash yarns

Bluefaced Leicester DK Yarn
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