From: Mechanical properties of white clay used as wall painting substrate material: measurement of strength and modulus of elasticity of simulated substrate material of wall paintings Hiten at Kondo, the main hall at Horyu-ji Temple
Coefficient
Value
\({a}_{1}\)
\(0.5899\)
\({a}_{2}\)
\(3.818\times {10}^{-2}\)
\({a}_{3}\)
\(8.875\times {10}^{-2}\)
\({a}_{4}\)
\(6.466\times {10}^{-3}\)