A method to prepare a metallic nanoparticle dispersion includes the steps of forming a metallic precursor dispersion or solution by adding a metallic precursor to a dispersion medium including: (a) a solvent according to Formula I, and wherein R1 and R2 represent an optionally substituted alkyl group, R1 and R2 may form a ring, (b) a carboxylic acid according to Formula II, R—COOH   Formula II wherein R is an optionally substituted C2-C7 alkyl, alkenyl or alkynyl group, reducing the metallic precursor with a reducing agent to form metallic nanoparticles, sedimenting the metallic nanoparticles to obtain a highly concentrated metallic nanoparticle dispersion comprising at least 15 wt % of metallic nanoparticles.