Most sweater stains are easily removed, if you act quickly. Different types of stains require different techniques. Protein stains are soaked in cold water because hot water will set the stain. Tannin stains need hot water to remove the stains. Before treating a stain, always check the garment tag for washing instructions because some sweaters, such as cashmere, need to be dry-cleaned.
Blot up excess liquid by placing the sweater with the stain facing down on absorbent paper towels.
Apply a laundry stain remover onto a white cloth. Blot the stain from the inside of the sweater, feathering the liquid toward the middle of the stain. This keeps the stain contained and prevents spreading.
Change the paper towel as needed, and continue until no further stain is transferring onto the paper towel.
Apply laundry stain remover to a sweater with protein stains from such things as blood, feces, vomit, urine, baby formula, pudding and ice cream. Then soak it in a tub of cold water for a half-hour. Swish the sweater around in the water.
Wash the sweater on a gentle cycle in warm water and detergent. If the sweater has a clothing care tag that instructs hand-washing, swish the sweater around in warm water and detergent.
Remove the sweater from the tub, and discard the tub water. Fill the tub with cold water and rinse the sweater by swishing it around in the cold water.
Remove the sweater from the water and lay it on a towel. Roll the towel up and squeeze out the water. Inspect the sweater for stains.
Lay the sweater on a dry towel or sweater-drying rack if the stain is gone. If the stain remains, treat the sweater with a laundry stain remover, then repeat steps 1, 2 and 3 before drying.
Tannin and Oil-Based Stains
Pretreat a sweater with stains from tannin, such as berries, coffee, juice, tea and tomato, or oil, such as cooking oil, lotions, grease and mayonnaise. Soak it in the warmest water it can tolerate, according to the garment tag. If the sweater is wool, wash it in warm water. Soak the sweater for a half-hour.
Add detergent, not soap, to the water and wash on gentle cycle. If the sweater indicates hand-washing, then wash by hand in a tub of warm water.
Rinse the sweater in warm water and check for stains. Dry the sweater by wrapping it in a towel and squeezing. Lay it flat to dry.
Apply a heavy-duty stain remover or detergent to a stain from a dye, such as ink, powdered drink mix, mustard and grass, and allow the sweater to soak for a half-hour. Rinse out the stain remover or detergent in cold water.
Soak the sweater in a mixture of 4 cups cold water and 1 cup fabric-safe bleach.
Wash the sweater in the hottest water allowable for the fabric using detergent.
Treat or dry-clean stains as soon as possible. The longer stains set, the harder they are to get out.
A powdered-detergent-and-water paste can substitute for laundry pretreat liquid.
Test stain-removal products on the underarm of the sweater to ascertain whether it will damage the garment.
Do not dry a sweater with a stain in the dryer because it will be almost impossible to remove the stain afterward.