The aim of this article is to report the creation of artificial, robust, and very hydrophobic materials with core-shell polyurethane-polydimethylsiloxane or polyurethane-poly(n-butyl acrylate) polymer microparticles. These latexes were prepared by polyaddition in cyclohexane with commercial or synthetic steric stabilizers. An easy one-step method based on the filtration of the colloidal particles was developed to obtain water-repellent fibrous materials such as paper or textiles that maintain stable properties even after several washing/drying cycles. (C) 2008 Wiley Periodicals, Inc.