Final answer:
Cotton is the sheerest fabric with an acid finish.
Step-by-step explanation:
Cotton is the sheerest of cotton cloths, and it can be finished with an acid treatment to give it crispness and stiffness. This finish helps the fabric retain its shape, even though it wrinkles easily. Despite being lightweight and delicate, cotton can still be durable and suitable for clothing and weaving.
Other fabrics mentioned, such as linen and silk, have their own unique properties and uses, but cotton is the sheerest fabric in this context.