Of all the things that can stain a couch, water is the last thing you'd expect to leave a mark. However, when too much water lands on the sofa, it can leave an ugly, telltale blemish on the upholstery. As the water evaporates, the minerals it contains are left behind, causing unsightly stains and discolorations. Fortunately, furniture covered in a cotton polyester blend is simple to clean. The fabric is durable and can be spot-cleaned with water-based solutions and weak solvents. This means the stain-causing sediment can be easily removed with a few common household items.
Wipe any visible stains with a damp sponge until the affected areas are evenly moist. Do not overwet the fabric.
Stack four to five paper towels on top of each other. Fold the stack into quarters, creating a thick, absorbent pad. Place the pad over the stain. Use more than one pad, if necessary, to ensure the entire water mark is completely covered.
Apply pressure to the towels for five minutes. On flat areas of the sofa, this is easily accomplished by placing a heavy bowl or large pan on top of the towels. On curved areas such as the back or sides of the couch, press down on the towels with your hands, soaking up as much excess water as possible.
Dry the couch with a hair dryer that has been set on "cool." Point the nozzle toward the damp material and allow the air to flow over the affected area until the fabric is dry to the touch.
Pour 1 tbsp. of distilled white vinegar into a small bowl. Add 1 tbsp. of water and stir until the two are well blended. Saturate the end of a cotton swab in this solution. Rub the cotton over an inside seam or other inconspicuous area. Wait for the test patch to dry and inspect the fabric carefully. If no color change is apparent, the solution is safe to apply to the couch.
Dab any stubborn stains with a soft sponge that has been dampened with the vinegar solution. Blot the stain gently, working from the outside edges toward the center. Wipe the solution away with a wet cloth. Pat the area dry with paper towels. If any discoloration remains, repeat the treatment.