Shape is probably the main topic for additive manufacturing (AM) processes. The flexibility of manufacturing parts of virtually any geometric form is the core feature of this technique. Shape can also be a critical topic when looking at the manufacturing process itself and not only the final part. In this study, we investigate the influence of shape at different stages of the process – the powder, the recoating blade and the manufactured part. First, discrete element method (DEM) simulations of the powder recoating process were performed using samples of PA 11 and PA 12. These samples were scanned with computed tomography (CT) to obtain their real shapes, which were then incorporated into the simulations. The results showed that a combination of low aspect ratio and high flatness led to improved packing properties compared to other shapes, including ideal spheres. Further numerical investigations were conducted using the best-performing powder sample with different blade geometries, revealing a clear dependency of the packed bed density on the blade shape. Finally, selective laser sintering was employed to manufacture particles of varying shapes, which were subsequently analyzed for inner porosity and surface roughness using CT measurements and DEM simulations. The results indicated that particles with lower convexity exhibited higher surface roughness and greater inner porosity (lower solidity). Despite being manufactured with the same technique, each particle shape denoted a different value for coefficient of friction and for particle density in DEM simulations to reproduce the experimental results. Given that DEM is widely supported by AM in studies involving non-spherical particles our results underscore the need for careful consideration of shape-induced defects throughout the manufacturing process.