Think of this as a "white dye" (we know, there's really no such thing). It's used to make fabric bright white after it's bleached. Works on all natural fabrics, including silks, that have already been whitened with bleach or peroxide. It does not make natural colored fabrics that are yellowish, and have not been bleached or peroxided, white. Things further whitened with optic whitener almost glow, they are such bright white. In fact, they do glow (a very bright almost bluish white), under blacklight, just like other fluorescent dyes or fluorescent paints, so are used for stage productions and scenery where this effect is needed for fabric. If you need to be able to tell if white fabric or clothing has also been optically whitened, just check it under blacklight! Occupies the same molecular sites on fabric that dyes do.
Use 1 tablespoon (10 grams) of this liquid per 1 pound of cotton fabric and soak with agitation in HOT water (160ºF) for 15 minutes. Rinse well in cold water.
Made in: UNITED STATES (USA)