A process for producing flat products from particulate material comprises the steps of forming relatively smooth, castable slurry comprising a suspension of particulate material in an aqueous solution, a film-forming binder material and a dispersion of a particulate synthetic resin in an aqueous solution, depositing a coating of this slurry onto a support surface and, heating the deposited coating to a temperature at which a component of the synthetic resin volatilises. The coating may be removed from the support surface as a flat product either before or after heating to volatilize a component of the synthetic resin.