Triarylmethanes having the formula RCHXR in which R is an aromatic nucleus containing one or more halogen atoms and an alkoxy, aralkoxy or cycloalkoxy group and X an aromatic nucleus which contains a sulphonic group and may also contain one or more halogen atoms are used for protecting wool, fur and other animal fibres against moths and other textile pests. The compounds, which may be applied dissolved in water or organic solvents may be prepared by alkylating, aralkylating or cycloalkylating all the hydroxy groups of halogenated hydroxy triarylmethanes having the formula R<1>CHXR<1> in which X is as above defined and R<1> is an aromatic nucleus containing one or more halogen atoms and a free phenolic group. In examples: (1) woollen yarn is worked in an aqueous bath containing 3 : 3<1> : 5 : 5<1> : 4<11>-pentachlor-2 : 2<1>-dimethoxy triphenylmethane-2<11> - sulphonic acid sodium salt, Glauber's salt and sulphuric acid; by adding a dyestuff to the bath the yarn is simultaneously dyed and protected; (2) 2 : 2<1>-dihydroxy - 3 : 3<1> : 5<1> : 5<1> - tetrachlortriphenyl methane-2<11>-sulphonic acid, obtained from benzaldehyde-o-sulphonic acid and 2 : 4<1>-dichlorphenol, is treated with dimethylsulphate, iso-butylbromide or benzylchloride; triarylmethanes obtained from benzaldehyde-o-sulphonic acid and 2-methyl-4-chlorphenol or from 3-chlorbenzaldehyde-6-sulphonic acid and 2 : 4-dichlorphenol may also be used; (3) 3 : 3<1> : 5 : 5<1>-tetrachlor-4 : 4<1>-dihydroxytriphenylmethane-2<11>-sulphonic acid is alkylated with dimethylsulphate; (4) 2 : 2<1>-dihydroxy-3 : 3<1> : 3<11> : 5 : 5<1>-pentachlortriphenylmethane 6<11>-sulphonic acid is alkylated with n-butylbromide. The Specification as open to inspection under Sect. 91 comprises also the manufacture and use as moth proofing agents of compounds having the formula RCHXR in which R is as above defined and X is hydrogen or an aromatic nucleus which may contain one or more halogen atoms or a sulphonic acid group or both. The proofing agents may be prepared by condensing one molecule of an aldehyde, e.g. formaldehyde, acetaldehyde or benzaldehyde with two molecules of an alkyl, cycloalkyl or aralkyl ether of a halogenated phenol or naphthol or mixtures thereof, in the presence of a mixture of sulphuric acid with acetic acid or zinc chloride or other acid condensing agent. In further examples: (1) wool yarn is dyed and proofed in a bath which contains besides alizarine direct blue, supramine yellow R, supramine red GG, Glauber's salt and sulphuric acid, one of the following proofing agents: 2 : 3<1> : 5 : 5<1> : 4<11>-pentachlor-6 : 6<1>-dimethoxytriphenylmethane - 2<11> - sulphonic acid, 2 : 2<1>-dimethoxy-3 : 5 : 3<1> : 5<1>-tetrachlortriphenylmethane - 2<11> - sulphonic acid, 2 : 2<1>-diethoxy-3 : 5 : 3<1> : 5<1>-tetrachlortriphenylmethane-2<11>-sulphonic acid, 2 : 2<1>-dipropyloxy-3 : 5 : 3<1> : 5<1>-tetrachlortriphenylmethane-2<11>-sulphonic acid, 2 : 2<1>-dibutoxy-3 : 5 : 3<1> : 5<1>-tetrachlortriphenylmethane-2<11>-sulphonic acid, 2 : 2<1>-di-iso-amyloxy-3 : 5 : 3<1> : 5<1>-tetrachlortriphenylmethane-2<11>-sulphonic acid, 2 : 2<1>-diallyloxy-3 : 5 : 3<1> : 5<1>-tetrachlortriphenylmethane-2<11>-sulphonic acid, 2 : 2<1>-dicyclohexyloxy-3 : 5 : 3<1> : 5<1>-tetrachlortriphenylmethane - 2<11> - sulphonic acid, 2 : 2<1>-dimethoxy - 3 : 5 : 3<1> : 5<1> - tetrachlortriphenylmethane-4<11>-sulphonic acid, 2 : 2<1>-dimethoxy-3 : 3<1>-dimethyl-5 : 5<1>-dichlortriphenylmethane-4<11>-sulphonic acid, 2 : 2<1>-diethoxy-3 : 5 : 3<1> : 5<1> : 4<11>-pentachlortriphenylmethane-6<11>-sulphonic acid, 2 : 2<1>-dibutoxy-3 : 5 : 3<1> : 5<1> : 4<1> pentachlortriphenylmethane - 6<11> - sulphonic acid, dicyclohexyloxy-3 : 5 : 3<1> : 5<1> : 4<11>-pentachlor triphenylmethane-6<11>-sulphonic acid, dicyclohexyloxy - 3 : 5<1> : 3<1> : 5<1> : 4<11> - pentachlortriphenylmethane - 6<11> - sulphonic acid, dibenzyloxy - 3 : 5 : 3<1> : 5<1> : 4<11> - pentachlortriphenylmethane-6<11>-sulphonic acid, 2 : 2<1>-dimethoxy-3 : 5 : 3<1> : 5<1> - tetrachlor - 4<11> - bromtriphenylmethane-6<11>-sulphonic acid, 2 : 2<1>-dimethoxy-3 : 5 : 3<1> : 3<11> - pentachlortriphenylmethane-6<11>-sulphonic acid, 2 : 2<1>-dibutoxy-3 : 5 : 3<1> : 5<1> : 3<11> - pentachlortriphenylmethane-6<11> - sulphonic acid, 2 : 2<1> - dimethoxy - 5 : 5<1> : 3<11> - trichlor - triphenylmethane - 6<11> - sulphonic acid, 2 : 2<1>-dibutoxy-3 : 3<1>-dimethyl-5 : 5<1> : 3<11>-trichlortriphenylmethane-6<11>-sulphonic acid, 2 : 3<1>-dibutoxy-3 : 5 : 2<1> : 4<1> : 6<1>-pentachlortriphenylmethane-4<11>-sulphonic acid; (2) woollen piece goods are protected by treatment with a solution containing cyclohexanone and 2 : 2<1>-di - n - butoxy - 5 : 5<1> - dichlordiphenylmethane, 2 : 2<1> - di - n - butoxy - 3 : 3<1> - 5 : 5<1> : 4<11>-pentachlortriphenylmethane or 2 : 2<1>-di-n-butoxy-3 : 3<1> : 5 : 5<1> : 5<11> : 2<11> : 4<11>-heptachlortriphenylmethane; (3) benzaldehyde-o-sulphonic acid is condensed with p-chloranisole, 2 : 4-dichloranisole, 2-methyl-4-chloranisole or ethers derived from halogen phenols or naphthol, and butyl, benzyl or p-chlorbenzylalcohol or cyclohexanol; (4) benzaldehyde-p-sulphonic acid is condensed with p-chloranisole; (5) 2 : 2<1>-dihydroxy-3 : 3<1> : 5 : 5<1>-tetrachlortriphenylmethane-2<11>-sulphonic acid is treated with iso - propyliodide; (6) 2 : 2<1> - dihydroxy-3 : 3<1> : 3<11> : 5 : 5<1>-pentachlortriphenylmethane 6<11>-sulphonic acid is treated with the methylether of ethyleneglycolchlorhydrin; the triarylmethane from benzaldehyde-2 : 4-disulphonic acid and 2 : 4-dichlorphenol or from benzaldehyde-p-sulphonic acid and a mixture of 2 : 4 : 6-trichlorphenol and 2 : 4-dichlorphenol is treated with butylchloride. Proofing agents containing iodine and alkoxyalkyl groups are mentioned. This subject-matter does not appear in the Specification as accepted.