Interactions of pulp fibers with moisture, including the presence of water in differently sized pores and irreversible effects of drying, are critical for many applications of pulps. X-ray scattering offers an unprecedented view into the nanostructure and packing of cellulose microfibrils under different conditions. However, interpreting scattering data requires special efforts. This research focuses on small-angle X-ray scattering analysis of moisture interactions in oriented pulp fibers. Small-angle scattering data analysis of pulps typically relies on examining a shoulder feature, which may correlate with microfibril spacing but does not consider any other contributions1,2. However, pulp fibers contain mesoscale pores between microfibril bundles, which contribute to the scattering and may in some cases dominate over the fibrillar contribution. We should consider all main structural component contributions to achieve a more accurate scattering data analysis.We have recently made progress in producing oriented pulp sample by utilizing dynamic sheet former combined with manual modifications. The preferred orientation enables the separation of isotropic scattering and allows more precise analysis of scattering from well-aligned microfibrils (see Figure). We measure small-angle and wide-angle X-ray scattering on well-aligned bleached softwood pulp fibers at different moisture contents, before and after oven drying. The anisotropic intensity shows a significant change with varying moisture content. As the moisture content decreases, the shoulder feature of the curve shifts to higher q values, while the scattering intensity decreases. This is explained by the decreasing distance between microfibrils during the drying process.2 This research is expected to provide insights about the effects of moisture removal and elevated temperature on irreversible fibril aggregation. Through detailed scattering analysis after the separation, we explore the scattering contributions from different structural components of pulp fibers and make a foundation for a comprehensive scattering data analysis method.