Table 3 Fracture toughness GIc of the oil paints investigated
Paint | Drying time [year] | GIc [J/m2] | Min–Max GIc [J/m2] | Location of crack propagation |
|---|---|---|---|---|
Lead white | 33 | 28 | 18–39 | Close to the polyester sheet substrate |
Lead white with litharge | 33 | 12 | 10–13 | |
Zinc white | 25 | 17 | 7–25 | |
Verdigris | 23 | 22 | 9–32 | |
Sap green | 25 | 83 | 31–180 | Complex pattern |
Titanium white | 31 | 22 | – | At the midplane |
Malachite | 33 | 35 | 33–37 | |
Raw umber | 31 | 15 | – | |
Red iron oxide (1998) | 24 | 17 | – | |
Red iron oxide (1992) | 31 | 40 | – | |
Synthetic ultramarine | 31 | 36 | – |