A composition in the form of a suspension, comprising (i) luminescent crystals of 3-500nm size of formula [M 1 A 1] a M 2 b X c, wherein: A 1 represents one or more organic cations selected from the group consisting of ammonium, formamidinium, guanidinium, imidazolium, pyridinium, pyrrolidinium, protonated thiourea, M 1 represents one or more alkaline metals selected from Cs, Rb, K, Na, Li, M 2 represents one or more metals selected from the group consisting of Ge, Sn, Pb, Sb, and Bi, X represents one or more anions selected from the group consisting of chloride, bromide, iodide, cyanide, thiocyanate, isothiocyanate and sulfide, a represents 1-4, b represents 1-2, c represents 3-9; and whereby in a compound of formula, A 1 is present, while M 1 may or may not be present; and (ii) surfactant selected from the group of non-ionic, anionic, cationic and zwitter-ionic surfactants; and (iii) optionally solvent, preferably selected from the group of aliphatic hydrocarbons, aromatic hydrocarbons, ethers, esters, alcohols, ketones; and (iv) polymer selected from the group consisting of acrylates and/or pre-polymer selected from the group consisting of acrylates, whereby said acrylates (iv) comprise or consist of monofunctional units of formula wherein: R 9 represents H or CH 3, R 10 represents a cyclic C5-25 alkyl group, or cyclic C5-25 alkenyl group or a substituted aryl group, n represents 0 or 1, and X represents a spacer from the group of alkoxylates comprising 1-40 carbon atoms and 1-10 oxygen atoms OR difunctional acrylates selected from the group consisting of 1,10-decanediol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, Neopentyl glycol dimethacrylate, tricyclodecane dimethanol diacrylate, Bisphenol A ethoxylate diacrylate, Bisphenol A ethoxylate dimethacrylate, modified fluorene-9-bisphenol diacrylate, modified fluorine-9-bisphenol dimethacrylate, and 1,3-buthylene glycol dimethacrylate; OR trifunctional acrylates selected from the group consisting of Ethoxylated trimethylolpropane triacrylate, trimetylolpropane triacrylate), and trimetylolpropane trimethacrylate; OR tetrafunctional (acrylates selected from the group consisting of Di(trimethylolpropane) tetraacrylate, and Pentaerythritol tetraacrylate; OR hexafunctional acrylates selected from the group consisting of Dipentaerythritol hexaacrylate. (i) luminescent crystals of 3-500nm size of formula [M 1 A 1] a M 2 b X c, wherein: A 1 represents one or more organic cations selected from the group consisting of ammonium, formamidinium, guanidinium, imidazolium, pyridinium, pyrrolidinium, protonated thiourea, M 1 represents one or more alkaline metals selected from Cs, Rb, K, Na, Li, M 2 represents one or more metals selected from the group consisting of Ge, Sn, Pb, Sb, and Bi, X represents one or more anions selected from the group consisting of chloride, bromide, iodide, cyanide, thiocyanate, isothiocyanate and sulfide, a represents 1-4, b represents 1-2, c represents 3-9; and whereby in a compound of formula, A 1 is present, while M 1 may or may not be present; and A 1 represents one or more organic cations selected from the group consisting of ammonium, formamidinium, guanidinium, imidazolium, pyridinium, pyrrolidinium, protonated thiourea, M 1 represents one or more alkaline metals selected from Cs, Rb, K, Na, Li, M 2 represents one or more metals selected from the group consisting of Ge, Sn, Pb, Sb, and Bi, X represents one or more anions selected from the group consisting of chloride, bromide, iodide, cyanide, thiocyanate, isothiocyanate and sulfide, a represents 1-4, b represents 1-2, c represents 3-9; and (ii) surfactant selected from the group of non-ionic, anionic, cationic and zwitter-ionic surfactants; and (iii) optionally solvent, preferably selected from the group of aliphatic hydrocarbons, aromatic hydrocarbons, ethers, esters, alcohols, ketones; and (iv) polymer selected from the group consisting of acrylates and/or pre-polymer selected from the group consisting of acrylates, whereby said acrylates (iv) comprise or consist of monofunctional units of formula wherein: R 9 represents H or CH 3, R 10 represents a cyclic C5-25 alkyl group, or cyclic C5-25 alkenyl group or a substituted aryl group, n represents 0 or 1, and X represents a spacer from the group of alkoxylates comprising 1-40 carbon atoms and 1-10 oxygen atoms OR difunctional acrylates selected from the group consisting of 1,10-decanediol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, Neopentyl glycol dimethacrylate, tricyclodecane dimethanol diacrylate, Bisphenol A ethoxylate diacrylate, Bisphenol A ethoxylate dimethacrylate, modified fluorene-9-bisphenol diacrylate, modified fluorine-9-bisphenol dimethacrylate, and 1,3-buthylene glycol dimethacrylate; OR trifunctional acrylates selected from the group consisting of Ethoxylated trimethylolpropane triacrylate, trimetylolpropane triacrylate), and trimetylolpropane trimethacrylate; OR tetrafunctional (acrylates selected from the group consisting of Di(trimethylolpropane) tetraacrylate, and Pentaerythritol tetraacrylate; OR hexafunctional acrylates selected from the group consisting of Dipentaerythritol hexaacrylate. R 9 represents H or CH 3, R 10 represents a cyclic C5-25 alkyl group, or cyclic C5-25 alkenyl group or a substituted aryl group, n represents 0 or 1, and X represents a spacer from the group of alkoxylates comprising 1-40 carbon atoms and 1-10 oxygen atoms