## 3 Results
### Results of the Cleaning Tests  
After confirming the presence of Paraloid(r) through FT-IR analysis, we decided to test the green products from Nasier-Brenta for their cleaning of the painted surface. The company's enzyme, Nasier Lapideo L02, as specified in the technical data sheet, is a ready-to-use product for stone surfaces which is specifically for the removal of organic patinas such as waves, drying oils, oleo-resinous paints, repaintings and synthetic compounds such as acrylic and vinyl esters and Paraloidr B72. In the first application, the aqueous gel based on the stabilized enzymes (lipases) had problems with adhering to the substrate due to its excessive fluidity, causing the solution to drip as soon as it was applied on the painting, thus preventing the correct functioning of the enzymes (Table 3). We then decided to contact the company, which provided a new sample specifically designed to overcome this problem (PHASE III in Table 3, Nasier L02 modified). This second formulation clearly had a greater density than the first solution, but it was still not enough to stably cling to the surface. Following a further consultation with the company, it was decided that covering the gel with a layer of transparent film would hold the gel to the surface and avoid its possible evaporation. Unfortunately, even with these adjustments, the tests did not achieve the desired results, as no consistent improvement was registered. We therefore decided to test the enzymatic cleaning mixture provided by CTS. As reported in their technical data sheet, the product is a mixture of purified lipase/esterase \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Test Number** & **Enzyme Mixture** & **Application Modality** & **Visible Result** \\ \hline \multirow{2}{*}{PHASE I-TEST I} & \multirow{2}{*}{[PERSON] L02} & By brush, on the surface for 20 min, & \\  & & inserting a sheet of Japanese paper between & No result \\  & & the surface and the enzyme mixture & \\ \hline PHASE I-TEST II & \multirow{2}{*}{[PERSON] L02} & By brush, directly on the surface for 45 min & \\  & & without paper & No result \\ \hline PHASE I-TEST III & \multirow{2}{*}{[PERSON] L02} & By brush, on the surface for 90 min, & \\  & & covering the enzymatic gel with & \\  & & transparent film & Partial removal is visible \\ \hline PHASE II–TEST I & \multirow{2}{*}{[PERSON] L02} & By brush, directly on the surface and & \\  & & covered with Japanese paper and & No result, the mixture is too \\  & & transparent film for 90 min & fluid and drips onto the wall \\ \hline PHASE II–TEST II & \multirow{2}{*}{Nasier L02} & The same as test I & The same result as test I \\ \hline PHASE II–TEST III & \multirow{2}{*}{[PERSON] L02} & The same as test I & The same result as test I \\ \hline PHASE III–TEST I & \multirow{2}{*}{[PERSON] L02 modified} & By brush, on the surface for 90 min, & \\  & & covering the enzymatic gel with & No result \\  & & transparent film—first application & \\ \hline PHASE III–TEST II & \multirow{2}{*}{[PERSON] L02 modified} & By brush, on the surface for 90 min, & \\  & & covering the enzymatic gel with & \\  & & transparent film—second application & Partial removal of the surface \\ \hline PHASE III–TEST III & \multirow{2}{*}{Nasier L02 modified} & By brush, on the surface for 90 min, & The removal of the surface \\  & & covering the enzymatic gel with & material is more evident than \\  & & transparent film—third application & in Test II, second application \\ \hline PHASE IV-TEST I & CTS product & By brush, for 5 min & No result \\ \hline PHASE IV–TEST II & CTS product & By brush, for 10 min & No result \\ \hline PHASE IV–TEST III & CTS product & By brush, for 45 min & \\  & & partial removal of the surface \\  & & material \\ \hline PHASE IV–TEST IV & CTS product & By brush, for 60 min & \\  & & material \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Summary of the cleaning tests performed on the painting using the enzymatic mixtures.