Hydrophilic dyes, reactive brilliant red K-2BP (C.I. Reactive red 24), acid fuchsin (C.I. Acid violet 19), and cationic brilliant red 5GN (C.I. Basic red 14), have been encapsulated into hydrophobic polystyrene (PS) latex particles using double miniemulsion technique. In this method, the water droplets containing dyes were first suspended in octane/styrene phase using lipophilic emulsifiers to form a primary miniemulsion. This miniemulsion was further dispersed in water and miniemulsified, followed by polymerization at high temperature to form dye/PS core-shell colorants. Experimental results show that this technique can cause as high as 80% of encapsulation efficiency for all three dyes, and obviously improve the waterproofing property and photostability of organic dyes. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 3615-3622, 2011