To minimize the effect of shape defects during 3D additive manufacturing, it becomes useful to understand the behavior of the material when it undergoes geometrical spatial variations meanwhile as cooling under fluid deposition. The present study shows whether there is a trend between the manufacturing deposition path, the solifdification between the successive addition of layers, the porosity and deformation of the material, and for example its optical properties. This multi-scale study is dedicated to the micro-, the meso- and the macro-structuration. A common bio-sourced polymer, the polylactic acid (PDLLA), was processed using the mode of Fused Deposition Fabrication (FDM or FFF) (DELTA 3D printer). Specific samples, described as ‘simple’, ‘relatively complex’ and ‘complex’ geometries, were designed to handle these peculiar tasks. Fine experimental analyses provide guidance for optimizing manufacturing conditions in FDM printing. Acknowledgements: The authors thank CNRS and MINES ParisTech/PSL for supporting this project.