What Is 4 Ply Yarn?
Basic 4 ply yarn is yarn consisting of four separate plies twisted together. Traditionally, ply was used as a measure of the thickness of yarn, sometimes corresponding directly to the size of knitting needles. With the abundance of different fibers, ply has become a less reliable indicator of yarn thickness, and so the number of plies is now simply a description of the yarn. 4 ply yarn, then, is simply yarn with four plies twisted together, just as 2 ply yarn is yarn with two plies. When 4 ply yarn is used as a description of the weight of yarn, it is essentially equivalent to medium-weight yarn. This is also sometimes called worsted weight yarn. Descriptions such as these do not always inform knitters of what size needles should be used with the yarn, and so it is important to knit a small amount of the material to test the needle size first. Most yarns come with a suggested needle size, and this is a good place to start.
