Dispersion comprises carbon nanotubes and graphene platelets in the mass ratio of 5:95-75:25. Independent claims are also included for: (1) preparing the dispersion, comprising combining carbon nanotubes and graphene platelets such that the mass ratio of carbon nanotubes to graphene platelets in the dispersion is 5:95-75:25; and (2) an electrically conductive film comprising carbon nanotubes and graphene platelets.