The interaction of platinum colloids encapsulated by an organic shell (Pt-col) with oxide (sapphire, quartz) and graphite single crystal substrates was investigated by AFM, STM and XPS. When dipped into aqueous colloid solutions at 20 degrees C, Pt-col particles and excess shell molecules are adsorbed onto these substrates. After annealing in vacuum at 500 degrees C the organic shell around the Pt colloids is decomposed for all supports used, and atomic force microscopy (AFM) images showed individual, sphere-shaped species on the alumina support, which are randomly distributed over the surface. They are attributed to Pt articles encapsulated by a carbonaceous shell. Oxidation in air at 650 degrees C removes this coating and leads to sintering of platinum. For the graphite support, after annealing in vacuum at 500 degrees C, large Pt particles are found that are stabilized by step edges on the graphite surface. This observation and the smaller amount of Pt adsorbed on carbon supports signal a stronger interaction of the Pt colloid with the oxide substrates.