The Double Knit (DK) yarn weight has the symbol 3. It is thinner and lighter than Aran. The Double Knit yarn is under the Worsted weight, but it refers to the Light-Worsted weight. The DK or the Light-Worsted yarn has an 8-ply thickness. Both the USA and UK standards refer to it as DK. This weight has a knit gauge of 21 to 24 stitches per 4 inches (10 cm.). You can see that when the yarn has a lower weight, it has a wider knit gauge. The Double Knit yarn works best on the needle size range of between 5 to 7 mm. for US size and 3.75 to 4.5 mm. for the UK. The DK is much lighter than Aran weight yarn. This type of yarn is best for lighter sweaters, leggings, and baby garments.