Processing of nanocellulose foams and aerogels involves two main steps: (1) preparation of a gel or wet foam from a dispersion; and (2) removal of the solvent by evaporation (oven drying), freeze drying, and supercritical drying preceded by solvent exchange. Moreover, foams can be structured directly from the dispersion by, e.g., freezing of the solvents [248].Nanocellulose foams and aerogels display densities ranging from 1 to 200 kg/m3, depending on the initial solid concentration, the possible expansion of the dispersion during the formation of the foam or structured gel, and shrinkage during solvent removal [248]. The porosity of aerogels and foams made of nanocelluloses can be even higher than 99%.