The invention comprises the heterocyclic-aromatic hydroxy ketones of the formula &lt;FORM:0973919/C1/1&gt; where X represents hydrogen, an alkyl group with 1-4 carbon atoms, a phenyl or a halogenated phenyl group, Y represents a free or etherified hydroxyl group and Z1 and Z2 may be identical or different and each represents a hydrogen atom or an alkyl group containing 1-4 carbon atoms.  The compounds are prepared by known methods, e.g. from the corresponding thiophene carboxylic acid or acid halide and the appropriate m-dialkoxy-benzene using a specified catalyst or by esterifying the m-alkoxyphenol with the thiophene carboxylic acid or acid halide and subsequently rearranging the ester to the o-hydroxy ketone by treatment with a Friedel-Crafts catalyst.  When the m-dialkoxy benzenes are used the reaction conditions are usually such that both the etherified hydroxyl groups are split off.  The resulting d-hydroxy ketone can be etherified by conventional methods, e.g. with alkyl halides.  When the acid halides are used in the first of the above methods any Friedel-Crafts catalyst can be employed, but for the reaction of the free acids with the di-alkoxy-benzenes borofluorine compounds, especially borontrifluoride, are necessary.  The compounds of the invention can be used as dye intermediates, but are most useful as light filters to protect a wide variety of materials from U.V. radiation (see Divisions A5, B5, C3, D1, D2 and G2). Examples 1-7 describe the preparation of compounds of the above formula in which Z1, Z2 and X are hydrogen and Y is an hydroxy, propoxy, isoamoxy or octoxy group, where Z1 and Z2 are hydrogen, Y is a hydroxy group and X is phenyl or 2, 5-dichlorophenyl and where Z1 is hydrogen, Z2 and X are methyl groups and Y is a hydroxyl group, the etherified compounds being obtained by alkylation of the corresponding free hydroxy compounds.ALSO:Macromolecular compounds are protected from U-V radiation by incorporation of a hydroxyketone of the formula &lt;FORM:0973919/C3/1&gt; wherein X represents hydrogen, a C1-C4 alkyl group, a phenyl or halogenated phenyl group, Y represents a free or etherified hydroxyl group and Z1 and Z2 are the same or different and each can represent hydrogen or a C1-C4 alkyl group. Protection may be effected by incorporating the light filter in the addition or condensation polymer before, during or after polymerization. Numerous specified materials include cellulose derivatives, addition polymers, e.g., polyvinyl chloride, polypropylene, polyethylene and polyacrylonitrile, condensation polymers, e.g. polyamides, polyesters, and phenol, urea and melamine-formaldehyde resins, natural and synthetic resins, e.g. epoxy, vinyl, and natural and synthetic rubbers, e.g. balata, guttapercha, polychloroprene, olefinic polysulphides, polybutadiene and its co-polymers. Example (10) describes the treatment of a hexamethylenediamine adipate polyamide mixed with titanium dioxide with a hydroxy ketone in which X, Z1 and Z2 are hydrogen and Y is a propoxy group and Z2 are hydrogen and Y is a propoxy group or Z1 and Z2 are hydrogen, Y is hydroxy and X is a 2, 5-dichlorophenyl group and extrusion of the resulting mixture.  In Example 11 the hydroxy ketone in which X, Z1 and Z2 are hydrogen and Y is an octoxy group is added to a paste of polyvinylchloride and dioctyl phthalate prior to forming a foil.ALSO:Compounds which are light filters and which may be incorporated in cosmetics, e.g. perfumes, bath salts, skin and face creams, powders, insect repellants and especially suntan oils and creams, to give protection against U.V. radiation, comprise hydroxy ketones of the formula &lt;FORM:0973919/A5-A6/1&gt; wherein X represents hydrogen, a C1-C4 alkyl group or a phenyl or halogenated phenyl group, Y represents a free or etherified hydroxyl group and Z1 and Z2 are the same or different and represent hydrogen or a C1-C4 alkyl group.ALSO:Textile materials, paper, paper stock and wood are protected from U.V. radiation by the incorporation of 0.1-5% of a hydroxy-ketone of the general formula &lt;FORM:0973919/D1-D2/1&gt; where X represents hydrogen, an alkyl group containing up to 4 carbon atoms, a phenyl or halogenated phenyl group, Y represents a free or etherified hydroxyl group and Z1 and Z2 may be identical or different and each can represent hydrogen or an alkyl group containing up to 4 carbon atoms.  The textiles may be in any desired form, e.g. filaments, fibres, yarns, woven, knitted or felt and may consist of natural materials such as wool, silk, cotton, hemp, linen, jute or ramie, semisynthetic materials, e.g. rayon, including spun rayon, viscoses or regenerated cellulose or they may be synthetic textiles obtained from addition polymers, e.g. polyacrylonitrile, polyethylene or polypropylene or from polycondensates such as polyesters or polyamides.  The light filter can also be incorporated in coating and dressing agents such as those based on starch and casein.  In Example 9 a fabric of polyamide fibres, prepared from hexamethylenediamine and adipic acid, is treated in a water/ethanol solution containing the adduct of 35 mols. ethylene oxide to 1 mol. stearyl alcohol with a hydroxy ketone in which X1 Z1 and Z2 are hydrogen and Y is a propoxy group.  In Example 12 a fancy paper prepared from a stock containing bleached sulphite or sulphate cellulose, zinc sulphide, aluminium sulphate, a paste containing an azo dye and water is covered with an untreated tissue or overlay paper and immersed in a bath consisting of a condensation product of melamine and formaldehyde and a solution of the hydroxy ketone, in which X, Z1 and Z2 are hydrogen and Y is a hydroxyl group, in dimethylformamide and water.  After removing excess resin and drying the paper is pressed together with a phenol paper and blocking sheets impregnated with melamine resin to give a laminate with improved fastness to light.