Use a detergent with optical brighteners for routine maintenance

Choose a laundry detergent that contains fluorescent whitening agents (also called optical brightening agents or OBAs) and use it for regular washing of white cotton and linen. Most major-brand detergents include these at approximately 0.05-0.1% concentration.

Why It Works

Optical brighteners are fluorescent compounds (typically stilbene derivatives) that absorb invisible ultraviolet light (340-370 nm) and re-emit it as visible blue light (420-470 nm). This makes fabric appear both whiter and brighter by increasing the total visible light reflected from the surface. Unlike bluing, which absorbs light, OBAs add light through fluorescence.

Tips

• Safe for both cotton and linen
• The effect is maintained through regular washing — stop using the detergent and the brightness fades as the OBA washes out
• If you prefer chemical-free options, detergents marketed as "free and clear" typically omit OBAs
• First commercially used in textiles in 1929, now the dominant whitening technology worldwide