The phenomenon you're describing, where black clothes have white spots or streaks after washing, is commonly known as "fading" or "bleaching." It occurs due to a variety of factors, but the most common reasons are:
Detergent Residue: When using too much detergent or not rinsing clothes thoroughly, detergent residue can remain on the fabric's surface. This can lead to discoloration, particularly on dark-colored garments.
Hard Water: If your water supply is hard, it contains high levels of minerals like calcium and magnesium. These minerals can interact with the dyes in dark clothes, causing them to fade and appear discolored.
Fabric Softeners: Some fabric softeners contain chemicals that can affect the color of dark fabrics. They may leave behind white spots or streaks.
Overloading the Washing Machine: If you overload the washing machine, clothes may not get enough space to move and rinse properly, leading to detergent and dirt buildup on the fabric.
Poor-Quality Dyes: Some dark clothes may be made with low-quality dyes that are more prone to fading.
To prevent white spots from appearing on your black clothes after washing, you can take the following steps:
Use Less Detergent: Follow the manufacturer's recommendations for detergent usage. In most cases, using less detergent than you might think is sufficient.
Choose a Suitable Detergent: Use detergents specifically designed for dark or black clothes. These detergents are formulated to be less likely to leave residue.
Rinse Thoroughly: Make sure to rinse your clothes thoroughly after washing to remove all traces of detergent.
Avoid Fabric Softeners: Avoid using fabric softeners or dryer sheets, as they can contribute to fading. Instead, try using alternatives like white vinegar as a natural fabric softener.
Sort Your Laundry: Separate dark-colored clothes from light-colored ones to avoid dye transfer. Washing dark clothes with other dark clothes reduces the risk of color fading.
Use Cold Water: Wash dark clothes in cold water. Cold water helps preserve the color and reduces the chances of fading.
Invest in Quality Clothes: Choose dark clothes made by reputable brands known for using high-quality dyes and fabrics.
Consider Water Softeners: If your water is hard, consider using a water softener to reduce the mineral content in the water.
By following these tips, you can help prevent the appearance of white spots on your black clothes after washing and keep them looking vibrant for longer.