## 4 Conclusions  
Additive technologies have the potential to be used in the manufacturing of many product categories. They are a prerequisite with regard to changing the current concept of supply chains, enabling the manufacturing of products with a complex internal structure, and they can effectively replace the conventional technologies used so far in some products' manufacturing. When deciding on their application, however, whether the technology used is suitable for a given product and how it affects its final quality needs to be assessed. At the same time, a suitable structure needs to be selected to be used for the product's manufacturing. When planning, a decision is often made between a lattice and gyroid structure. Based on the mentioned facts, the present research was carried out, aiming to compare the impact of the materials and technologies used on the quality of porous structures, represented by lattice and gyroid structures. The research was carried out on two types of test specimens: one with a lattice structure and the other with a gyroid structure. Then, the individual specimens were assessed using the industrial tomography method. The results of computed tomography allow us to conclude that with SLS technology, care must be taken to remove excess powder, which may not be easy in complex structures. With the specimens manufactured by the FDM technology, the difference in the visual assessment of the printing quality is obvious. Black specimens are visually of better quality than red ones, and they deviate less from the reference values for specimens' surfaces and the actual and nominal comparison. Red specimens are more accurately manufactured, and their external dimensions deviate less from the reference dimensions. Given the volume of the specimens, it is impossible to unequivocally state which samples are better manufactured; the differences between them are small. The porosity assessment of specimens manufactured by the FDM technology, i.e., the red and black ones, does not provide the desired results, as a significant number of pores emerge on the surface and the \"gaps\" between the layers cannot be considered as standardized pore shapes; thus, their software assessment is problematic, and the results are only informative. The result cannot be generalized to the entirety of FDM technology manufacturing; it only concerns the specimens tested by us. This is due to the technology, the specimens' shapes, and the material used. The comparison of SLS and FDM manufacturing implies that SLS specimens yield better results in terms of the material volume, the specimen's external dimensions, and the nominal and actual comparison to the reference models. The result is worse in the surface assessment, which is caused by the excess powder on the surface. The gray specimens' porosity is higher than expected, which may be due to the specimens' thin walls and their overall design. For the above reasons, the porosity results of SLS and FDM manufacturing cannot be compared. We observe a discrepancy between the visual specimens' assessment and the measurement of roughness. With the FDM technology, in red and black specimens, we obtain contrasting results. Visually, the black specimen is better than the red one, but its porosity indicates the opposite. When comparing the printing of Flexfill 92A specimens, the result obviously depends on several parameters, such as the specific printer, the product's design, and, finally, the operator's experience, with a significant impact on manufacturing. Roughness measurement with an optical microscope, based on the principle of image layering, is the most suitable method by which to analyze the experimental specimens' surface structure. The color material differentiation is a disadvantage in terms of reflection for the red Flexfill 92A material, and despite the use of various options for the exposure time and brightness, the lattice structure could not be scanned.