A method for dissolving cellulose in which the cellulose based raw material is admixed with a mixture of a dipolar aprotic intercrystalline swelling agent and an ionic liquid at a temperature of 25° C. to 180° C. for a time sufficient to dissolve the cellulose based raw material. The molar ratio of dipolar aprotic intercrystalline swelling agent to ionic liquid is 0.05 to 1.5 moles of dipolar aprotic intercrystalline swelling agent to 1 mole of ionic liquid. Dipolar aprotic intercrystalline swelling agents do not include imidazole based agents or amine based agents.