# Influence of Printing Substrate on Quality of Line and Text Reproduction in Flexography
## 4 Results and Discussion
### Analysis of Text Deformation
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & \multicolumn{8}{c}{**Text Size 6 pt**} \\ \hline
**Sample Types** & **Area** & **Area** & **Perim.** & **Perim.** & **Area** & **Area** & **Perim.** & **Perim.** \\  & **(mm\({}^{2}\))** & **DEV (\%)** & **(mm)** & **DEV (\%)** & **(mm\({}^{2}\))** & **DEV (\%)** & **(mm)** & **DEV (\%)** \\ \hline  & \multicolumn{8}{c}{**Character \"r\"**} \\ \hline  & TARGET & 0.28 & 0 & 4.04 & 0 & 0.32 & 0 & 5.36 & 0 \\ \hline
**Negative** & \begin{tabular}{c} UCTD \\ OPP \\ FILM \\ CTD \\ \end{tabular} & 0.26 & \(-7.1\) & \(5.15\) & \(27.5\) & \(0.30\) & \(-6.3\) & \(6.69\) & \(24.8\) \\  & \
\begin{tabular}{c} OPP \\ FILM \\ CTD \\ \end{tabular} & 0.24 & \(-14.3\) & \(4.74\) & \(17.3\) & \(0.27\) & \(-15.6\) & \(6.24\) & \(16.4\) \\  &
\begin{tabular}{c} UCTD \\ OPP \\ FILM \\ CTD \\ \end{tabular} & 0.27 & \(-3.6\) & \(4.64\) & \(14.9\) & \(0.31\) & \(-3.1\) & \(6.07\) & \(13.2\) \\ \hline
**Positive** & \begin{tabular}{c} UCTD \\ OPP \\ FILM \\ CTD \\ \end{tabular} & 0.31 & 10.7 & 5.65 & 39.9 & 0.35 & 9.4 & 7.36 & 37.3 \\  & \
\begin{tabular}{c} OPP \\ FILM \\ CTD \\ \end{tabular} & 0.33 & 17.9 & 4.60 & 13.9 & 0.38 & 18.8 & 6.03 & 12.5 \\  &
\begin{tabular}{c} UCTD \\ OPP \\ FILM \\ CTD \\ \end{tabular} & 0.32 & 14.3 & 4.56 & 12.9 & 0.37 & 15.6 & 5.94 & 10.8 \\ \hline \hline \multicolumn{8}{c}{**Text Size 8 pt**} \\ \hline
**Sample Types** & **Area** & **Area** & **Area** & **Perim.** & **Perim.** & **Area** & **Area** & **Perim.** & **DEV (\%)** & **(mm)** & **DEV (\%)** \\ \hline  & \multicolumn{8}{c}{**Character \"r\"**} \\ \hline  & TARGET & 0.47 & 0 & 5.43 & 0 & 0.56 & 0 & 7.18 & 0 \\ \hline
**Negative** & \begin{tabular}{c} UCTD \\ OPP \\ FILM \\ CTD \\ \end{tabular} & 0.45 & \(-4.3\) & \(6.91\) & \(27.3\) & \(0.53\) & \(-5.4\) & \(8.95\) & \(19.6\) \\  & \
\begin{tabular}{c} OPP \\ FILM \\ CTD \\ \end{tabular} & 0.42 & \(-10.6\) & \(6.50\) & \(19.7\) & \(0.50\) & \(-10.7\) & \(8.24\) & \(14.8\) \\  &
\begin{tabular}{c} CTD \\ OPP \\ FILM \\ CTD \\ \end{tabular} & 0.46 & \(-2.1\) & \(6.33\) & \(16.6\) & \(0.55\) & \(-1.8\) & \(8.08\) & \(12.5\) \\ \hline
**Positive** & \begin{tabular}{c} UCTD \\ OPP \\ FILM \\ CTD \\ \end{tabular} & 0.53 & \(12.8\) & \(7.92\) & \(45.9\) & \(0.63\) & \(12.5\) & \(9.91\) & \(38.1\) \\  & \
\begin{tabular}{c} OPP \\ FILM \\ CTD \\ \end{tabular} & 0.56 & \(19.1\) & \(6.26\) & \(15.3\) & \(0.66\) & \(17.9\) & \(8.04\) & \(12.0\) \\  &
\begin{tabular}{c} CTD \\ OPP \\ FILM \\ CTD \\ \end{tabular} & 0.54 & \(14.9\) & \(6.19\) & \(14.0\) & \(0.64\) & \(14.3\) & \(7.94\) & \(10.6\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Results of measuring of area and perimeter for two text sizes of 6 pt and 8 pt printed in positive and negative shapes on three different printing substrates. Smaller deviations of area values from target value on paper, especially on coated paper (up to \(-3.6\%\) in negative shape), are associated with good absorption of paper as a printing substrate; therefore, the ink quickly penetrates into the structure of the material and spreads less on the surface of the material [32]. In text deformation in a negative shape, mild closures of characters occur due to the spread of ink. For this reason, the character area is smaller than in the text deformation in a positive shape. Perimeter analysis assesses the edge degradation of the characters, which is extremely important for visibility, fidelity character shape and text legibility. The deviations from the target value on coated paper and OPP film are extremely similar (up to 3% in negative shape, and 1.5% in positive shape) and significantly smaller than on uncoated paper, which also means smaller edge raggedness of the text (Figure 6).