Always make sure you use a good quality detergent and use the correct amount. Don’t overload the washing machine either. Not using enough detergent and overloading can cause poor results and even redistribution of grease and marks onto laundry.
If your laundry sometimes comes out of the washer with greasy dark stains on coloured garments (or stains with a waxy appearance) here are a few possible causes -
- Oil and grease spills during meals or during cooking can be particularly stubborn to remove from polyester: Pre-treat with something like Ariel Liquid and wash at the highest temperature recommended on the care label of the article
- Make sure you don’t use too much fabric conditioner : Pre-treat with Ariel Liquid and soak in warm water for 10 minutes before washing as normal
My mum always put some Swarfega on any greasy marks on clothes before putting them in the washing machine, and it seems to work. Try on a bit of the fabric you won’t see first though, just to check.