The most common type of underarm garment stains are those caused by antiperspirants and deodorants. During the wearing of a garment, sweat combined with the antiperspirant or deodorant can be transferred and deposited on the armpit areas.
These deposits are not readily removed by a normal washing cycle and over time build up, leading to the formation of stiff, uncomfortable patches of clear or white residue deposits which can be chalky or greasy to the touch, as well as a visible stain.
Deposits on darker or deep colored garments tend to manifest themselves as a visible white stain resulting in a bleached or faded appearance of the armpit area. On white or light colored garments, the appearance of these deposits can be more pronounced, often becoming discolored to an unsightly yellow or brown.
This is more prevalent on affected garments that have been exposed to heat such as in the washer and dryer and in particular ironing.