It protects against stains on clothes. Black stays black and white stays white longer.
WHAT IS IT THAT CAUSES YELLOWING STAINS IN THE UNDERARM AREA OF LIGHT-COLOURED CLOTHING?
Yellow stains gradually build up from wash to wash. Various factors contribute to the formation of these stains: Anti-perspirant actives, the skin’s sebum and sweat absorbed in the textile interact with water and the detergent. This chemical reaction produces yellow-coloured deposits that remain stuck in the fibers. With every washing the fabric becomes more and more yellowish and inflexible.
WHY DOESN’T EVERYONE GET THESE YELLOW MARKS IN THE ARMPITS OF THEIR CLOTHES?
Actually, everyone will eventually get yellow stains, if he/she uses anti-perspirant products. The extent to which someone develops yellow stains can, however, differ a lot from individual to individual depending on the composition of perspiration and oil on the skin and how much one perspires. For some people the stains build up very slowly, so that it takes very long until they finally become visible to the naked eye. These people might have impression that they do not get yellow stains at all. Another reason for having this impression could be that someone uses a deodorant which is free of anti-perspirant actives.