Remove water stains from polyester fabric by soaking the fabric in water and drying evenly so that the edges of the stain fade into the rest of the fabric. If the stain is not removed using this method, it may be something other than water.
Water stains are caused by water not drying evenly on polyester fabric. The easiest way to remove them is to soak the entire garment in water and to dry it evenly. Submerge the garment in clean water, and take it out. Do not wring the excess water, but rather, shake it from the fabric.
Lay the garment on a clean towel, and lay a second towel on top of the garment. Gently press to squeeze out as much water as possible. Hang the garment to dry. Check that it is drying evenly so as not to create new water stains. Pay especially close attention to thicker parts of the garment, such as the collar, pockets or cuffs. These take longer to dry.
To control the drying process more precisely, dry the garment evenly with a blow dryer. If the fabric must be dry cleaned, add moisture with a steamer instead of soaking it in water. Otherwise, the process is the same.