SpeedBlock OB-184 is a fluorescent whitening agent, with excellent chemical and thermal stability, for use in ink and coating applications. SpeedBlock OB-184 is used in white and pastel tones where the degree of whiteness of the paint/ink needs intensifying. SpeedBlock OB-184 will mask the yellow self colour of some formulations and will increase the deep tone of blue/black inks. SpeedBlock OB-184 is recommended for use at concentrations between 0.02 - 5.0%. The actual use level chosen depends on the particular application and end user requirements.