## 3 Results
### Determination of Linear Shrinkage  
Using the iNEXIV vision system, the \(x\) and \(y\) coordinates of the marker centers were measured on samples marked with crosses. Based on these measurements, the primary parameter analyzed in the study was the resultant displacement (\(dr\)) of the measured point from its nominal position. Positive values of the determined displacement indicated that the measured points were located farther from the center of the sample than their nominal positions suggested. Negative values, on the other hand, indicated that the points had moved closer to the center. The axes of symmetry divided the samples into four quadrants. The obtained \(dr\) values were averaged for corresponding points from different quadrants. The results, presented graphically for the solid plate and the one with a hole, for the shortest and longest exposure times, are shown in Figure 14.  
To determine the influence of sample type (solid and with hole), exposure time (\(t\)), and the nominal distance of the marker from the center of the sample (\(d\_nom\)) on marker displacement (\(dr\)), a regression model was developed that included linear effects and two-factor interactions. Using a significance level of \(\alpha\) = 0.05, backward regression was performed. In the final model, all three examined factors, as well as the interaction between sample type and exposure time, were found to be statistically significant (Table 3). The model was statistically significant but exhibited moderate fit (adjusted coefficient of determination R\({}^{2}\)adj = 0.70). Therefore, the model can be used to identify dominant trends and relationships between factors--which was the purpose of its development--but it is not suitable as a predictive model. The influence of the studied factors and the interaction effect are presented in Figures 15 and 16. The most significant influence on marker displacement due to shrinkage was the marker's distance from the center of the sample. As expected, the farther the marker was from the center, the greater its displacement. Larger displacements  
Figure 13: UV intensity on the LCD surface after applying the correction mask.  
To calculate the correction for dimensional changes of the samples due to shrinkage, the relative displacement of each marker was first calculated using the following formula:  
\[dr\%=\frac{dr}{d\_nom}\times 100\% \tag{4}\]  
In Figure 17, which shows the relationship between relative displacement and sample type as well as the distance of the markers from the center of the sample, it can be observed that the differences in relative marker displacement (dr%) between different sample types decrease as the nominal distance (r_nom) increases. For r_nom > 10 mm, the differences in dr% stabilize at approximately \(-\)0.36%. This value was determined as the median of the dr% values for both solid and hole samples. For the purpose of determining the shrinkage value to be set in the printing settings for solid samples, the linear shrinkage was assumed to be s = 0.36%, corresponding to the overall shrinkage of the sample. Shrinkage and its potential compensation concern only the external contour. The case of the sample with a hole is more complex. The displacement of markers at the external contour relative to the nominal value differs from the displacement of markers at the internal contour. To compensate for shrinkage, the average shrinkage value of s = 0.44% was adopted based on the average dr% value for samples with hole.  
Figure 16: Interaction plot of sample type and exposure time.  
Figure 17: Change in relative displacement as a function of sample type and the distance of the markers from the center of the sample (the presented lines are trend lines).