We have demonstrated that hardly luminescent TCNQ becomes highly luminescent in crystals of melamine. The method of encapsulating colorful guest molecules in a transparent large gap host material can be utilized for many other host-guest combinations. This opens up new avenues of exploration for advanced optical materials. with mole percentages of TCNQ to melamine of 0.04, 0.16 and 1.25 %, as freshly prepared (top) and after 24 hours (bottom). The spectra demonstrate that the solutions contain only DCTC -as freshly prepared. These solutions were used for the crystallisation reported in the manuscript. After 24 hours, the peaks of DCTC -have become weaker. This indicates that the DCTC -decomposes slowly in aqueous THF. by the down arrow) to exhibit the highest emission at λ ex ∼ 390 nm (labeled as S RET