Azo dyes containing one or more metals, and specially suitable for colouring the varnishes known by the Registered Trade Mark "Zapon," are obtained by treating, in presence of alkali but in absence of salts of hydrosulphuric acid, azo dyes which contain neither sulphonic nor carboxylic groups and which are derived from o-oxydiazo compounds and aromatic amine or oxy-compound coupling components, with one or more hydroxides of mordanting metals or with products of reaction of such hydroxides, in presence of alkali, with organic compounds containing one or more hydroxy groups. such as polyvalent alcohols, phenols, tannins, sugars, cellulose derivatives, or lignin material, The following examples are specified: (1) The dyestuff 2 : 1-aminonaphthol --> b -naphthol is heated for 24 hours at 74-78 DEG C. with a solution containing chromium hydroxide and excess of caustic potash; the product, dissolved in Zapon varnish, yields a violet coating of good covering power on sheet aluminium. (2) The dyestuff 4-chloro-2-aminophenol --> resorcinol is boiled for 16 hours under reflux with a solution containing chromium hydroxide, excess of caustic potash, and glycerol; the product, dissolved in Zapon varnish, yields a brown-red coating of very good fastness to light on sheet metal; the products similarly obtained from the dyestuff 2-aminophenol --> b -naphthylamine and ferric and nickel hydroxides give similar reddish-brown coatings. (3) The dyestuff 4-nitro-2-aminophenol --> resorcinol is boiled first with dilute ammonia solution and thereafter under reflux with an ammoniacal solution of zinc oxide. (4) The dyestuff 4-chloro-2-aminophenol --> resorcinol is boiled for 3 hours under reflux with a solution containing ferric chloride, excess of caustic soda and glycerol; the product, dissolved in Zapon varnish, yields brown coatings, fast to light, on sheet aluminium; the product similarly obtained from the dyestuff 6 - nitro - 4 - chloro - 2 - aminophenol --> b -naphthylamine and cobaltous chloride gives similar dull blue-green to pure green-black coatings. (5) The dyestuff 4-nitro-2-aminophenol --> resorcinol is boiled for 3 hours under reflux with alkaline sodium stannate solution; the product, dissolved in Zapon varnish, yields yellow coatings, fast to light, on sheet aluminium. (6) The dyestuff 4-nitro-2-aminophenol --> resorcinol is boiled for 3 hours with a solution containing ferric chloride, aluminium sulphate, copper sulphate, excess of caustic soda and glycerol; the product, dissolved in Zapon varnish, yields brown coatings, very fast to light, on sheet aluminium. (7) 4 to 5 parts of the cobalt compound of the dyestuff 4-chloro-2-aminophenol --> b -naphthol are dissolved in 1000 parts of a finished Zapon varnish; the product yields transparent wine-red coatings on metal, glass, wood, leather, celluloid, silk &c., and by incorporating suitable additions is convertible into a mat or covering varnish. (8) The dyestuff 4-sulphamido-2-aminophenol --> b -naphthol is boiled for 3 hours under reflux with a suspension of nickel hydroxide in caustic alkali containing glycerol; the product colours Zapon varnish brownish red. Specifications 104,045, 186,635, and 297,687, [all in Class 2 (iii), Dyes &c.] are referred to. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the use as diazo components of o-carboxyamines and the use as coupling components of cyclic compounds containing a methylene group capable of coupling, and includes the following further examples: (1) The dyestuff anthranilic acid --> b -naphthylamine is boiled under reflux with a solution containing zinc sulphate and an excess of caustic soda; the product, soluble in water, dissolves in Zapon varnish and yields powerful yellowish orange lakes. (2) The dyestuff 4-chloro-2-aminophenol --> 1-phenyl-3-methyl-5-pyrazolone is boiled for 3 hours with a solution containing aluminium and cobalt compounds, excess of caustic soda, and glycerol; the product, slightly soluble in water, dissolves in Zapon varnish, the solutions yield vivid orange coatings, fast to light, on sheet aluminium; the corresponding cobalt and aluminium compounds give redder and yellower shades respectively. (3) The dyestuff 4-chloro-2-aminophenol --> 2:3-oxynaphthoic acid is heated with a solution containing chromium hydroxide and an excess of caustic potash; the product colours Zapon varnish violet. This subject-matter does not appear in the Specification as accepted.ALSO:Azo dyes, soluble metal compounds of; lakes.-Azo dyes containing one or more metals are obtained by treating, in presence of alkali but in absence of salts of hydrosulphuric acid, azo dyes which contain neither sulphonic nor carboxylic groups and which are derived from o-oxydiazo compounds and aromatic amine or oxy compound coupling components, with one or more hydroxides of mordanting metals or with products of reaction of such hydroxides, in presence of alkali, with organic compounds containing one or more hydroxy groups, such as polyvalent alcohols, phenols, tannins, sugars, cellulose derivatives, or lignin material. The products are especially suitable for colouring the varnishes known by the registered trade mark "Zapon." The following examples are specified. (1) The dyestuff 2 : 1-aminonaphthol --> b -naphthol is heated for 24 hours at 74-78 DEG C. with a solution containing chromium hydroxide and excess of caustic potash, the product, insoluble in water, dissolves in Zapon varnish to a blue-violet solution yielding a violet coating of good covering power on sheet aluminium. (2) The dyestuff 4-chloro-2-aminophenol --> resorcinol is boiled for 16 hours under reflux with a solution containing chromium hydroxide, excess of caustic potash, and glycerol; the product, slightly soluble in water, dissolves in Zapon varnish, the solution yielding a brown-red coating of very good fastness to light on sheet metal; the products similarly obtained from the dyestuff 2-aminophenol --> b -naphthylamine and ferric and nickel hydroxides give similar reddish-brown coatings. (3) The dyestuff 4-nitro-2-aminophenol --> resorcinol is boiled first with dilute ammonia solution and thereafter under reflux with an ammoniacal solution of zinc oxide. (4) The dyestuff 4-chloro-2-aminophenol --> resorcinol is boiled for 3 hours under reflux with a solution containing ferric chloride, excess of caustic soda, and glycerol; the product, slightly soluble in water, dissolves in Zapon varnish, the solution yielding brown coatings, fast to light, on sheet aluminium; the product similarly obtained from the dyestuff 6-nitro-4-chloro-2-aminophenol --> b -naphthylamine and cobaltous chloride gives similar dull blue-green to pure green-black coatings. (5) The dyestuff 4-nitro-2-aminophenol --> resorcinol is boiled for 3 hours under reflux with alkaline sodium stannate solution; the product, soluble in water, dissolves in Zapon varnish, the solution yielding yellow coatings, fast to light, on sheet aluminium. (6) The dyestuff 4-nitro-2-aminophenol --> resorcinol is boiled for 3 hours with a solution containing ferric chloride, aluminium sulphate, copper sulphate, excess of caustic soda, and glycerol; the product, slightly soluble in water, dissolves in Zapon varnish, the solution yielding brown coatings, very fast to light, on sheet aluminium. (7) 4 to 5 parts of the cobalt compound of the dyestuff 4-chloro-2-aminophenol --> b -naphthol are dissolved in 1000 parts of a finished Zapon varnish; the product yields transparent wine-red coatings on metal, glass, wood, leather, celluloid, silk, &c., and by incorporating suitable additions is convertible into a mat or covering varnish. (8) The dyestuff 4-sulphamido-2-aminophenol --> b -naphthol is boiled for 3 hours under reflux with a suspension of nickel hydroxide in caustic alkali containing glycerol; the product, slightly soluble in water, dyes silk from an acetic acid bath, and colours Zapon varnish brownish-red. A table is given showing the colours of the following metal compounds obtained by the process of the invention: the lead compound from 4-nitro-2-aminophenol --> resorcinol, the nickel compound from 2-aminophenol --> resorcinol, the cobalt compound from 4 - sulphamido - 2 - aminophenol --> b -naphthol, the manganese compound from 5-nitro-2-aminophenol --> b -naphthol, the cobalt compound from 4-chloro-2-aminophenol --> b -naphthylamine, the tin compound from 4-chloro-2-aminophenol --> resorcinol, the aluminium compound from 2-aminophenol --> b -naphthol, the zinc compound from 1 : 2-aminonaphthol --> a -naphthol, the cobalt compound from 6-nitro-4-chloro-2-aminophenol --> b -naphthylamine, the ferric (50 per cent)-nickel (50 per cent) compound from 2-aminophenol --> b -naphthol, the nickel (20 per cent)-copper (80 per cent) compound from 4-chloro-2-aminophenol --> resorcinol, the ferric (50 per cent)-tin (50 per cent) compound from 2-aminophenol --> b -naphthylamine, the ferric (50 per cent)-manganese (50 per cent) compound from 4-sulphamido-2-aminophenol --> b -naphthol, the ferric (30 per cent)-aluminium (70 per cent) compound from 2-aminophenol --> b -naphthol, the ferric (80 per cent)-cobalt (20 per cent) compound from 4-chloro-2-aminophenol --> b -naphthylamine, the cobalt (50 per cent)-aluminium (50 per cent) compound from 4-sulphamido-2-aminophenol --> b -naphthol, the cobalt (60 per cent)-copper (40 per cent) compound from 4-chloro-2-aminophenol --> resorcinol, and the aluminium (20 per cent)-copper (30 per cent)-cobalt (50 per cent) compound from 5-nitro-2-aminophenol --> b -naphthol. In further examples, (9) wool is dyed a fast dark marine blue by treatment for 1/2 hour at 60 DEG C. followed by boiling for 1/2 -\ba3/4 hour in a sulphuric acid bath containing the dyestuff of example (7), and (10) ordinary or loaded silk is dyed a fast brownish red by treatment for 3/4 -1 hour at 80 DEG C. in