Nanoparticles have been increasingly studied due to their unique properties. The deposition of uniform layers with these nanoparticles however is a crucial step in many of their applications. In this work, ultrasonic spray coating is the technique of choice as it is by design well-suited for the deposition of nano-suspension dispersions. The influence of different deposition parameters, ink composition and post-treatment are subject of study in this paper. It is shown in this work that (mass-) production of uniform nanoparticle layers is possible due to the narrow distribution of the droplet size and the deagglomeration of the particles during ultrasonic spray coating. It is also demonstrated that with ultrasonic spray coating it is possible to deposit an eco-friendly, water-basednanoparticle inkinto layers with desired thickness and morphology. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim ; The authors would like to thank financial support from the Interreg project SolarFlare. A.E. is a FWO (Research Foundation Flanders) postdoctoral fellow. J.V.-M.S., C.K.A., and A.C.G.L. are grateful to AUCANI and ProInt - USP for the scholarships. ; mini-emulsions; nanoparticles; polystyrene; thin films; ultrasonic spray coating