Table 1.

Emission lifetimes of typical luminescent materials found in cultural heritage.

Material	Emitting Molecule or Process	Emission Lifetimes
Protein and oil-based binders, varnishes, adhesives and glues	Organic molecules	ps to tens of ns
Organic natural and synthetic pigments	Organic molecules	ps to tens of ns
Semiconductor pigments	Band gap recombination Trap levels	ps to ns μs
Doped semiconductor pigments	Impurities	μs to hours
Minerals	Intrinsic or extrinsic defects in the crystal lattice	μs to ms