Many organic materials tend to go yellow in appearance through breakdown under UV or visible light. The breakdown products absorb blue light which in turn create the yellow appearance in daylight. To counter this effect it is possible to add materials which absorb UV light and then transmit it in the blue region. They have the ability to make whites appear ‘brighter’ as the eye interprets this blueness. The materials which provide this effect are called Optical Brighteners or alternatively are sometimes referred to as 'fluorescing whitening agents'.

Optical Brightener OB

Optical Brightener OB is a fluorescent optical brightener that shows:

• brilliant blueish whitening effects
• excellent heat resistance
• high chemical stability
• good compatibility in a wide range of resins

Optical Brightener OB is recommended for applications such as:

• overprint varnishes where it is used to mask the yellowish self colour and also to intensify the brilliance of white and coloured prints
• black and blue printing inks to increase their deep tone
• printing inks for quick identification, security and safeguard against forgeries (ie banknotes)
• packaging inks as promotional tool or as tracer for packaging lines

Due to the intrinsic light fastness properties of optical brighteners, Optical Brightener OB is recommended for indoor use only.