Skip to content

Undyed vs. Dyed yarn

  • by

If you’ve ever ordered the same yarn in undyed and dyed versions, you may have noticed that they can sometimes look like entirely different yarns. For example, the photo below shows two skeins of Whitefaced Woodland Light DK yarn, both containing 300m per 100g. The left-hand skein is dyed, the right-hand undyed.

A skein of dyed Whitefaced Woodland Yarn next to a skein of undyed Whitefaced Woodland Yarn

The dyed skein looks larger, plumper and thicker than the undyed skein, yet they are both exactly the same. The reason for the difference is simple.

During spinning, oils are used on the wool to allow it to travel through the spinning machinery easily. Different wools, machines and mills use different quantities, which is why it effects some yarns more than others.

This is also the reason why it’s always a good idea to swatch yarn and wash the swatch before choosing needle/hook size for a project. Even commercially dyed yarn can change when it is washed. This is because the fibres are dyed before they are spun, so any oils used during the spinning of the yarn are still coating the yarn.