Raw silk, also known as Silk Noil, is made from the fibers produced by silkworms. It contains sericin, a natural protein that may have healing properties, leading to its use as a top layer on cloth pads. It is almost always a natural off-white color, and has a slightly rough texture.
Unlike raw silk, processed silk is very soft and smooth. While not absorbent, it can make a luxurious top layer to a pad.