Shirt collar stains are caused by the sweat of the neck and hair coming into contact with the neckband of the shirt. It is essential to clean the collar while the stain is still fresh, so that the stain is easier to remove. The more you wash the collar with the stain on it, the more difficult the stain will be to remove. With just a few simple materials, you can remove collar stains and prevent throwing away perfectly good shirts.
Remove the collar stays from the shirt, if they can be removed. The collar stays are small strips of plastic or metal inserted under the crease of the collar, helping the collar stay flat and straight against the collarbone. Some shirts have removable collar stays, while others have collar stays sewn in.
Apply shampoo or dishwashing detergent directly onto the stain, and scrub it into the stain with a toothbrush. Let the shampoo or dishwashing detergent soak into the stain for 15 to 30 minutes.
Check the collar to see if the stain is gone. If it is, then launder the shirt as you normally would. If the stain is still there, dab a stain removal product on it according to the directions, then launder the shirt.
Read your shirt label before applying the stain remover to make sure the stain remover won't damage the shirt.