The absorbency of fabric is determined by the types of fibers it's made of. Natural fibers like wool and cotton are absorbent, as are manufactured fibers like rayon and acetate. Synthetic fibers like nylon, polyester, and acrylic are not absorbent. High-absorbency fabrics absorb water-based stains. While resistant to water-based stains, synthetic fabrics like polyester are more prone to oil and grease stains. If you have natural fabric furniture or clothing, you can make it more stain-resistant by using chemical finishes like Scotchgard Fabric Water Shield. However, this type of treatment isn’t typically long-lasting. Alternatively, resin treatments done at the manufacturing level can provide longer-lasting protection but may make the fabric less absorbent of sweat, leading to discomfort when wearing or sitting on it.