The engineering of microstructured cellulose is of interest for a wide scope of applications. Nevertheless, the formation of materials from cellulose still poses several challenges, such as retaining the inherent mechanical properties of cellulose, its high thermal and chemical resistance as well as tunable nano-scaled permeability. We report the formation of microstructured cellulose membranes from crystalline cellulose with tunable properties. The 3D morphology of the assembly, its mechanical toughness, permeability and optical properties can easily be tuned through this simple fabrication process. Particularly the thickness of the crystalline cellulose membranes can be finely tuned in the micrometer range while maintaining the inherent properties pertaining to crystalline cellulose. The fiber network properties were evaluated by scanning electron microscopy, several optical microscopy techniques (polarized microscopy, bright field etc.) and by ultraviolet-visible spe
ctroscopy. The framework developed herein for the 3D microstructuring of cellulose is expected to have implications across all disciplines involving the use of crystalline cellulose because it allows micrometer precision in the fabrication of mechanically robust cellulose materials while bearing a high degree of versatility in properties and structure. For instance the preparation technique allows one to form nanostructured, micro-scaled, scaffolds that would prove useful in food and biomedical research.