Monodispersive synthetic opal particles were formed by the method of Stober et al. [J. Colloid Interface Sci. 26 (1968) 62] and were made hydrophobic by reacting them with 3-(trimethoxysilyl)propyl methacrylate. Groups of particles were dissolved in chloroform and were spread at the air/water interface using a Nima trough. Each group studied consisted of particles, which had almost identical diameters. Isotherms were obtained and these are illustrated. The use of an optimum value of surface pressure and a high level of hydrophobicity made it possible to deposit good quality multilayers by the Langmuir-Blodgett method but we found that the Langmuir-Schaefer method was easier to use for less hydrophobic particles. The layers obtained were studied by scanning electron microscopy and we present the images obtained from these results. (C) 2003 Elsevier Science B.V. All rights reserved.