Basic technical information about yarn and its care
Key technical terms
We supply this information on each of our Blacker Yarns, and have also produced longer and more detailed information sheets on each of these terms.
- Length: wool yarn stretches, some types more than others, and the density varies. So a 50g ball, or 100g skein, may be of a different length, even when it’s the same thickness, depending on these variables. See our information sheet, ‘How long is a ball of wool’. Some patterns, particularly those from US designers, give yardage, rather than weight in specifying the yarn quantity required.
- Specification: the specification of a yarn describes its thickness, amount of twist and the number of plies. Different specifications work in different ways: thicker yarns knit up more quickly than finer ones, while denser or drapier yarns will produce a different fabric to a more bulky and bouncy style. By definition, thicker yarns will have lower yardage for their weight than finer ones. Some of this is also due to the fibre: so yarns from different sheep produce different results: you can go to our Meet the Animals pages for more information.See our more detailed information sheet ‘Yarn weights’.
- Tension/Gauge: the specification of a yarn gives it a range of tensions and gauges, depending on what size of needles or hooks is used. So a Guernsey yarn is traditionally worked on fine needles and makes a very dense, wind-proof fabric. The tension or gauge is vital to give you the right size in a pattern and you should always try out a swatch to check whether you get the same number of rows and stitches for the same dimensions as the pattern states. If not, you need to alter your tools: larger needles will make the tension looser, and the item larger, while small needles will do the opposite. Do not be afraid to work with two needles one size apart if you need to get an exact tension and your knitting style requires it. The knitter, of course, is the final ingredient in the mix and not only does everyone work at a slightly different tension, but usually they also work their knit and purl stitches at differing tensions.
- Knitting needles: there are plenty of charts showing knitting needle and crochet needle sizes because naturally they differ in different places across the world. Needles may also be single pointed, double pointed or circular and both hooks and needles are made of various materials.See our basic info sheet ‘Needles and Hooks’which lists in mm, UK and US sizes.








