\(\begin{equation} I=\frac{\left(105\cos\left(90-\frac{mL}{2}\right)\right)^2\ h}{2n^2}\left[1-\frac{0.81}{1+2.5\left(\frac{105\cos\left(90-\frac{mL}{2}\right)}{2\times210\sin\left(90-\frac{mL}{2}\right)}\right)^2}\right] \end{equation}\)
Equation (13) expresses that with a decrease in the number of lines and increase in the linewidth, the second area moment increases. Figure 10a presents the load-deflection curve obtained from the SCS fabricated with = 4 and 10 and the second area moment derived from the results. The SCS results fabricated with = 6 and 8 are presented in Supporting information (Figure S2). The translucent lines in the graph indicate the results of the three measurements, and the opaque lines indicate the averaged results. First, we evaluated the stiffness of the SCS fabricated with = 10 (Figure 10a(i)). The upper left of the photographs presents the SCS for = 10 with = 5 mm, 10 mm, and 15 mm. From the load-deflection curve, with an increase in the linewidth, the slope of the initial stage increased, and the stiffness increased. As a result, the second area moment increased. Therefore, as expressed as Equation (12) and (13), with an increase in the linewidth and amplitude of the SCS for = 10, the stiffness of the structure with a higher second area moment increased. Moreover, as can be seen from the load-deflection curve at = 15 mm, the first peak load was 3.24 N, thus indicating that the structure can withstand a load of approximately 330 g. This indicates that a sheet of paper with a mass of 5.72 g can withstand a load greater than its mass by a factor of 57.7, thus acting as a SCS.  The microstructure mentioned by Bassik et al. can withstand a load greater than its mass by 7700; however, it has the maximum load capacity of 0.883 g because the structure is small \cite{bassik2009microassembly}. Using the proposed paper-printing self-folding technology, we successfully tailor-made a large-scale corrugated structure with various stiffness properties and high load capacity. Thereafter, we evaluated the stiffness of the structure with = 4 (Figure 10a(ii)). For the structure with n = 4, there was no increase in the slope of the initial stage with an increase in the linewidth, and the stiffness results exhibited a different trend from that expressed by Equation (12). Furthermore, despite the decrease in the number of lines, the second area moment was lower than = 10, which exhibited a different trend from that expressed by Equation (13). In addition, although the SCS was fabricated with the same linewidth, there was a significant variation between the three tests. We found that the structural characteristics can be typical for self-folded corrugated structures such as the SCS. 
Figure 10b presents the stiffness distribution of the fabricated SCS. Due to the reaction between the paper and printed solution, the stiffness of the crease parts increased in the SCS. However, the stiffness of the straight-line parts connecting the creases remained low because no new components were added, and no hard compression was used to process it. Therefore, with a decrease in the number of lines, there were more straight-line parts with low stiffness; thus, there was a higher probability of deformation during the three-point bending test. Figure 10c presents the structure with = 4 and 10 immediately after the end of the three-point bending test. Compared with the structure with = 10, the structure with = 4 underwent with significant deformation. Therefore, we considered that the increase in stiffness with an increase in amplitude could not be confirmed for the structure with= 4. Thus, increasing the linewidth and amplitude is not sufficient to design an SCS with high stiffness; considering that the stiffness distribution over the entire SCS is required.
 Furthermore, the results revealed that the load repeatedly increased or decreased in all the load-deflection curves. The results may indicate that the SCS buckle repeatedly during the three-point bending test. First, at the peak of the load, the mountain folds buckled, and the load decreased. After the buckling of the mountain folds, the residual part of the SCS received additional compressive load, which caused the buckling and increase or decrease of the load. This process was repeated during the test, thus causing the load to increase or decrease repeatedly. We attributed this to the flexibility of the paper material.