Ply: the single. Most basic form of yarn
1-ply yarn is a single strand of fiber twisted together to create a thin and delicate yarn. Because of its single-ply construction, this type of yarn can be softer and more flexible than multi-ply yarns, making it ideal for creating lightweight and breathable fabrics. 1-ply yarns are often used for delicate lace patterns, shawls, and lightweight garments. They can also be a great choice for creating texture and visual interest in knitted or crocheted fabrics.
Two-ply Yarns. Yarns becomes stronger
2-ply yarn is made of two strands of fiber twisted together to create a slightly thicker and more durable yarn than a 1-ply yarn. The twisting of the two strands together creates a strong and cohesive yarn that is less likely to break or pill than a single-ply yarn. The added strength of 2-ply yarn makes it a great choice for creating high-wear items like socks, mittens, and sweaters that will see a lot of use.
Three-ply yarns. The more plies, the better
3-ply yarn is made of three strands of fiber twisted together to create a medium-weight yarn that is thicker and more durable than a single-ply or 2-ply yarn. The added twist and thickness of 3-ply yarn can create a plump and rounded appearance that is great for showing off stitch definition and creating beautiful textures in knitted or crocheted fabrics. Because of its added strength, 3-ply yarn is a great choice for creating garments and accessories that will see a lot of use, such as hats, scarves, and sweaters.
Four-ply and more. The plies do not nest together
4-ply yarn and higher ply yarns refer to the number of strands of fiber that are twisted together to form a single yarn. While 1-ply, 2-ply, and 3-ply yarns are relatively common, 4-ply and higher ply yarns are less common but can offer some unique benefits. The extra strand of fiber can provide additional structure and density, making 4-ply yarn a great choice for creating more substantial projects like sweaters, blankets, or even rugs.