Suspensions of nanometer to micrometer sized particles are spread over solid surfaces to develop nano- and micro-sized structured materials with desirable structural and optical properties. A wedge film is formed by placing a droplet of an aqueous suspension of latex particles on a smooth solid surface. The drop dries and the evaporation flux drives the latex particles into the wedge film. The particle structuring phenomenon in the wedge film was directly observed using reflected light microinterferometry. Both the contact angle dynamics and the particle trajectories inside the wedge film were monitored. A sensitive infrared camera is used to monitor the temperature gradient over the droplet surface. The evaporation flux creates the temperature gradient over the drop surface, thereby inducing the Marangoni flow. The Marangoni flow drives particles outward from the central part of the region of the drop into the drop periphery. The effect of surfactants on the particle flow was investigated. Under the confinement effect of the wedge film, the flow assembles the particles into a 2-D array structure. The experimental results were rationalized in terms of a theoretical model.