Table 2: Naschekin [17, page 331], Emittance, ε (Emissivity).

MaterialTemperature, T°CEmittance, 𝜀

Bright aluminum 50 ÷ 500°C0.04–0.06
Bright copper20 ÷ 350°C0.02
Steel50°C0.56
Asbestos board20°C0.96
Glass 20 ÷ 100°C0.91–0.94
Baked brick 20°C0.88–0.93
Tree20°C0.8-0.9
Black vanish40 ÷ 100°C0.96–0.98
Tin20°C0.28