# Print Quality Analysis of Stone Paper and Coated Sticker Paper Used in Screen Printing
## 4 Results and Discussions
### Rub Resistance  
The rubbing resistance of UV-based ink was relatively high on both papers. Only the adhesion on the coated sticker paper was slightly higher (between 99.26 and 99.82%). Such a case can be attributed to the cellulosic structure of coated sticker paper and the good absorption of liquid UV ink. The polymerization of UV-based ink during drying played a significant role in the high rubbing resistance of both paper types (97-99%) (Table 6) [66; 67]. For the rubbing resistance of solvent ink, adhesion on the stone paper was higher than that on the coated sticker paper (between 86.98 and 90.05%). Solvent ink accumulated on the non-absorbent surface of the stone paper and dried as a resistant layer (Table 6). The printing density of the coated sticker paper was generally higher than that of the stone paper. The UV-based-ink-printed surfaces exhibited stable rubbing resistance on both papers (Figure 7, Table 6). \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline  & & \multicolumn{4}{c}{**Stone Paper**} & \multicolumn{4}{c}{**Coated Sticker Paper**} \\ \hline \multirow{3}{*}{**Mesh Count**} & \multirow{3}{*}{**Ink Type**} & \multicolumn{2}{c}{**Printing Density**} & \multicolumn{2}{c}{**Printing Density**} & \multicolumn{2}{c}{**Percentage**} & \multicolumn{2}{c}{**Printing Density**} & \multicolumn{2}{c}{**Printing Density**} & \multicolumn{2}{c}{**Percentage**} \\  & & **before Rubbing Test** & **after Rubbing Test** & **Rubbing Test** & **before Rubbing Test** & **after Rubbing Test** & **after Rubbing Test** & **Rubbing Test** \\ \cline{3-12}  & & **Density** & **SE** & **Density** & **SE** & **\%** & **Density** & **SE** & **Density** & **SE** & **\%** \\ \hline
90 tpc & solvent & 2.69 & 0.02 & 2.34 & 0.03 & 86.98 & 2.81 & 0.01 & 2.16 & 0.05 & 76.75 \\
120 tpc & solvent & 2.65 & 0.01 & 2.31 & 0.02 & 87.40 & 2.80 & 0.01 & 2.48 & 0.03 & 88.80 \\
140 tpc & solvent & 2.61 & 0.01 & 2.35 & 0.02 & 90.05 & 2.71 & 0.02 & 1.78 & 0.07 & 65.60 \\
90 tpc & UV & 2.27 & 0.00 & 2.23 & 0.01 & 97.94 & 2.06 & 0.01 & 2.05 & 0.01 & 99.51 \\
120 tpc & UV & 1.91 & 0.01 & 1.90 & 0.01 & 99.47 & 1.95 & 0.01 & 1.94 & 0.01 & 99.82 \\
140 tpc & UV & 1.79 & 0.01 & 1.78 & 0.01 & 99.07 & 1.81 & 0.00 & 1.80 & 0.01 & 99.26 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Stone paper and coated sticker paper rubbing resistance. Figure 7: Ink rubbing resistances on stone paper and coated sticker paper. In Figure 7a, the solvent ink layers printed with three different mesh counts on the stone paper showed regular abrasion with the number of rubs. However, as can be seen in Figure 7b, the UV ink layers printed with the same mesh count on the same paper layer showed high rub resistance. This resistance can be explained by the polymerization and curing of the UV ink, which form a stable surface. A similar observation was made on the coated sticker paper; as shown in Figure 7c, wear increased parallel to the number of rubs in the printing of the solvent ink on the coated sticker paper. In contrast, the rub resistance of the UV ink printed on the coated sticker paper was found to be quite high (Figure 7d). When evaluating the rub resistance of solvent inks independently, a consistent decrease is observed in Figure 7c. This reduction can be attributed to the fact that solvent-based inks undergo physical drying through evaporation and do not form a polymeric structure. Such drying does not provide as stable a structure as UV-cured inks. In UV curing, a photopolymerization process is utilized. Consequently, this process leads to rapid polymerization, which facilitates the swift drying of the ink film and provides a more stable film layer compared to solvent-based inks [24,30]. The color changes in the substrates printed with solvent ink are shown by the \(\Delta\)E values before and after the rub resistance tests, as provided in Table 7. Due to the absorptive nature of coated paper, the solvent ink was absorbed into these surfaces and did not form as strong a bond as on the stone paper.