Due to the durability and versatility of the fabric, polyester is a common choice for many household applications. Curtains, window treatments and sheers are often made of either polyester or a polyester blend. Dust and other household airborne debris can land on polyester sheers, causing them to turn a dingy, yellowish color. But don't despair -- you can turn your polyester sheers white again very quickly.
Fill the washer with cold water, and add the sheers. Polyester is a washable fabric and quite durable, so even a sheer can be washed with no problems.
Add in the baking soda and vinegar once the washer begins agitating. This will cause some fizzing and bubbling as the ingredients collide and react. Vinegar is a natural cleaner and so is baking soda. When you combine them, you get twice the cleaning and whitening power to lift away that yellowish build-up on the threads of your sheers.
Allow the full wash cycle to run. This will not only lift away the dirt, but it will also spin it out and rinse your sheers, so when you remove them, they will be strikingly white.
Remove the sheers and hang them to dry. If possible, hang the sheers from the top so they don't crease before you put them back up on your windows. If you have to hang them over the line, move them several times as they dry to avoid creases and unsightly lines. Polyester tends to keep its shape, and doesn't wrinkle or crease as badly as cotton or other fabrics.
When the sheers are completely dry, rehang them.