Colour brightening-When garments made of cotton or cotton blends have been washed several times, they tend to get a 'fluffy' look and the colours become duller. This effect is due to the formation of microfibrils that become partly detached from the main fibres. The light falling on the garment is reflected back to a greater extent giving the impression that the colour is duller. These fibrils, however, can be degraded by the cellulase enzyme, restoring a smooth surface to the fibre and restoring the garment to its original colour.