## Materials and Methods
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Test** & **Standard** & **Factor** & **Symbol** & **Type** & **Unit** & **Low Level (\(\mathbf{-1}\))** & **High Level (\(\mathbf{+1}\))** \\ \hline \multirow{4}{*}{Tensile} & \multirow{4}{*}{ASTM D638} & Material & A & Categorical & - & ULTEMTM 9085 & ULTEMTM 9085 \\  & & & & & Tan & Black \\  & & & Geometry & B & Categorical & - & Type I & Type IV \\ \hline \multirow{4}{*}{Flexural} & \multirow{4}{*}{ISO 178} & Material & A & Categorical & - & ULTEMTM 9085 & ULTEMTM 9085 \\  & & & & & Tan & Black \\  & & Geometry & B & Categorical & mm & 122 & 165 \\  & & Material & A & Categorical & - & ULTEMTM 9085 & ULTEMTM 9085 \\  & & & Geometry & B & Categorical & mm & 122 & 165 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Experimental plans. Factors, levels and responses for each investigated test. The selected printing settings are summarized in Table 2. These parameters were selected according to past experience to minimize the presence of internal voids [19]. All the specimens were oriented flatwise on the XY plane. To avoid negative notch effects leading to premature failure, as reported in some previous research [3], the start and stop positions for printing the tensile specimens were set in one corner in the grip zone (Figure 2). The viscoelastic behavior of the two material types was investigated using a DMA Tritec 2000 (Triton Technology Ltd., Nottinghamshire, UK) by single cantilever geometry and sample size (\(10\cdot 5\cdot 2\)) mm\({}^{3}\). The tests were carried out at 1 and 10 Hz with 2 \({}^{\circ}\)C/min heating rate from 25 \({}^{\circ}\)C to 250 \({}^{\circ}\)C.  
A Shimadzu DSC 60 (Shimadzu, Kyoto, Japan) was used for calorimetric glass transition temperature (\(T\)g) determinations. The apparatus was calibrated in enthalpy and temperature by following the procedure discussed in [20]. Afterwards, the enthalpy calibration was checked by the \begin{table}
\begin{tabular}{l c c} \hline \hline
**Parameters** & **Unit** & **Value** \\ \hline Infill & \% & 100 \\ \hline Infill type & & Solid \\ \hline Support type & & ULTEM Support \\ \hline Raster angle & deg & 0/90 \\ \hline Layer height & \(\mu\)m & 254 \\ \hline Tip & & T16 \\ \hline Shrink factor (x) & & 1.01 \\ \hline Shrink factor (y) & & 1.01 \\ \hline Shrink factor (z) & & 1.0097 \\ \hline Contours width & mm & 0.508 \\ \hline Part raster width & mm & 0.508 \\ \hline Raster to raster air gap & & 0 \\ \hline Contour to raster air gap & & 0 \\ \hline Contour to contour air gap & & 0 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Printing conditions for the preparation of the specimens. Figure 1: Dimensions (in mm) of the specimens. (**a**) Tensile test specimens (ASTM D638 type I, IV); (**b**) flexural test specimens; (**c**) short-beam shear specimens. melting of fresh indium, showing an agreement with the literature standard within 0.25% [21]. This happened while the temperature calibration was checked by several scans with fresh indium and tin, showing an agreement within 0.08% with respect to the literature values [21]. The DSC scans have been performed on samples of about \(6.0\cdot 10^{-3}\) g, held in sealed aluminum crucibles at a heating rate of 10 \({}^{\circ}\)C/min and static air atmosphere. The investigations were carried out in a range of temperatures from room temperature up to 300 \({}^{\circ}\)C and each scan was performed in triplicate. The considered values were averaged from those of three runs, the maximum difference between the average and the experimental values being within \(\pm 1\)\({}^{\circ}\)C.  
The mechanical properties of printed specimens were measured by using an Instron 5985 universal testing machine (Instron, Milan, Italy) equipped with a load cell of 10 kN. For each test, the tools required for the various standard tests were installed. System control and data collection were performed using the Blue Hill 3.61 software (Instron, MA, USA). Following the DoE method, we randomized the testing order for all samples and test types.