Dried water stains on fabric can be removed by dampening the whole area with water or steam and allowing it to dry. For dampening with steam, the stained fabric can be held in the steam above a boiling kettle. Garments that can be ironed should be pressed while still damp.
This method can be used to clean cotton, linen, nylon, polyester and wool. It also helps clean rayon, silk, acetate, acrylic fiber, synthetic or wool carpet, triacetate, modacrylic, olefin and spandex.
Water spots on fabric occur when sizing or finishing agents within the fabric are dislocated and then dry in rings.