The macroscopic properties, e.g. mechanical, of wood-based materials depends on their molecular and nanoscale structure. For example, the deformation of wood cells can be directly related to their hierarchical architecture and to a stick–slip mechanism at the molecular and nanometer scale [1]. Observing the length scales up to micrometer is necessary to understand the wood-based materials’ structure-process-function relationship. Both neutron and X-ray scattering come into play, especially due to their ability of observing structural changes in situ during processing of materials. We focus on the two main components of wood, namely lignin and cellulose nanofibrils (CNF), as sustainable raw materials for material applications. First, we highlight small- and wide-angle X-ray scattering (SAXS/WAXS) to relate the nanoscale and molecular structure of lignin-based bulk thermosets with their macroscopic mechanical properties [2]: They are determined by the molecular π- π -stacking of the phenyl rings in the aromatic structure of lignin. In order to replace synthetic colloids for optical applications, lignin colloids (LC) are well-established. We use spray deposition as industrially relevant and scalable method to fabricate sustainable ultraviolet (UV) light protective, yet transparent lignin colloid/CNF thin films [3]. Here, CNFs act as structure-guiding nanoporous network to facilitate the self-assembly of the lignin colloids. Grazing incidence SAXS (GISAXS) allows for deriving the lignin colloid nanostructure and agglomeration behavior in the presence of the CNF network. In situ studies using GISAXS and neutron scattering during processing of CNF-based hybrid materials are highlighted for two examples. For core-shell-colloid-CNF hybrid thin films, the film formation regimes during spray deposition are elucidated (liquid phase with initial solvent evaporation, drying phase with self-assembly of the constituents, dried film)  [4]. In the last example, we highlight in situ neutron scattering to understand the reversible nanostructural changes during cyclic relative humidity changes in CNF-conductive polymer hybrid thin films [5].