Bluing (fabric)
PRODUCT USED TO IMPROVE OPTICAL WHITENESS OF CLOTHING OR TEXTILES
Laundry blue; Washing blue; Laundry bluing; Keen's Oxford Blue; Bluing (fabrics); Dolly blue
Bluing, laundry blue, dolly blue or washing blue is a household product used to improve the appearance of textiles, especially white fabrics. Used during laundering, it adds a trace of blue dye (often synthetic ultramarine, sometimes Prussian blue) to the fabric.