Why is 100% CD single jersey fabric breathable?

Single Jersey fabric, including 100% CD Single Jersey, is a type of knit fabric made using a single set of needles in a warp-knitting machine. The resulting fabric has a smooth face and a looped back, which can restrict airflow to some extent. The loops on the back side of the fabric create a barrier that hinders air circulation, making it less breathable compared to more open-knit fabrics like mesh or pique.

Breathability in fabrics is determined by factors such as the type of fiber used, the weave or knit structure, and the density of the fabric. While cotton, as a natural fiber, does have some inherent breathability, the specific construction of Single Jersey knit fabric limits its ability to allow air to pass through freely.
If breathability is a top priority for a particular garment or application, other fabric choices like cotton mesh, linen, or certain synthetic performance fabrics with moisture-wicking properties might be more suitable.
In summary, 100% CD Single Jersey fabric is comfortable to wear due to its softness and natural fiber properties, but it may not be the most breathable option compared to fabrics specifically designed for maximum ventilation and airflow.