Note: do not wash these rags in the washing machine. Indeed, detergents contain an optical brightener, whose goal is to make the machine more "bright" light. To do this, is injected into the washing of silica (= sand) fine, which is housed in the fabric, and increases the amount of light reflected. If you clean these micro-fiber cloths with lye, you contaminate with silica that will scratch your lenses and optical thereafter.
As stated on the product itself: if you need to clean the cloths, wash them by hand with warm water. Let them dry and use no form of laundry product type. Water and nothing else: no soap, no softening, nothing.
