## 2 Materials and Methods
### Build Layout
#### 2.3.2 Part Location Assignment  
To mitigate systematic errors arising from the position in the build chamber, each specimen is randomly assigned to one of the defined locations in the build space. However, because 45 positions are defined for each build, and only 37 specimens should be produced, a plan must be derived for the remaining eight positions. First, the positions cannot be left open because this could disturb the temperature distribution throughout the build; hence something should be produced in all 45 positions. To ensure that an equal amount of energy is applied to all positions, the same specimen will, therefore, be used to fill this space. Furthermore, these specimens shall not be part of the main study, and they should, therefore, be differentiated from the main group somehow, and it was decided to make the part build orientation 270 degrees about the x-axis--an orientation outside the scope of the main study, while still being somewhat comparable. This allows using these specimen as a control group to further facilitate comparative analyses across builds and positions. In order to keep the variation between the specimens to a minimum, the superfluous positions were restricted to eight defined positions in the build space to be duplicated in all three builds. The rear-center position at (170, 270) for all z-layers was selected because of the assumed similarity to the front-center position (170, 70) and also had the benefit of not being first or last relative to the recoater for any layer. The final three positions excluded from the main study are located in the front-right corner at z-layers 1, 3, and 5. These positions should be similar to the other corners and are evenly distributed along the z-layers to provide evenly distributed data points along this dimension of the build space. The specimens produced at eight extra positions are referred to as \"anchor\" specimens inspired by their function as fixed data points in the experiment design.  
The randomization was conducted in Microsoft Excel by applying the RAND function to assign a floating-point number in the range of [0, 1) to every orientation and then sorting the list with respect to the random number. The list of orientations was then aligned with the list of available positions in the build space, effectively using the list index to determine the position in the build according to the numbering of Figure 4. The assignment of orientations to positions is available in Table A1 in the Appendix A.  
Figure 3: The first step of build space segmentation. (**a**) The build space as seen from the top; (**b**) the build space as seen from the front of the machine.  
The build layout was prepared in the software Materialise Magics 23.01, where the artifact design was imported as a binary STL file, and the mass labeling-function was utilized to create 45 duplicates with the appropriate labeling as displayed in Figure 5. The labeled models were translated to their predetermined position in accordance with the build space segmentation by center coordinates (note that Magics defines the center point of a part as the geometric center of the bounding box). Finally, the models are reoriented into their predetermined part build orientation by counterclockwise rotation about the x-axis.  
Figure 4: Numbered positions for the specimens and the positions of the “anchor” specimens. (**a**) The bottom layer of specimens numbered 1 through 9. Position 3 is reserved anchor specimens for z-layers 1, 3, and 5, while position 8 is reserved anchor specimens for all z-layers; (**b**) a front view showing the first three numbers of each layer (the front row).  
Figure 5: Illustration of the labeling scheme applied in the experiment. The writing is imprinted and embedded in the stereolithography (STL) file during layout preparation in Magics 23.01.